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Magnolia Road & I-135 Break-In-Access Study MAGNOLIA ROAD & 1-135 BREAK-IN-ACCESS STUDY Prepared for the City of Salina, Kansas October 1993 ....... BUCHER, WILLIS & RATLIFF ..,...... ENGINEERS I PLANNERS I ARCHITECTS I I I I I I I I I I I I I I I I I I I MAGNOLIA ROAD/I-13S Break-in-Access Study TABLE OF CONTENTS I. INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Study Area .... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Purpose of the Project........................................... 3 Distances to and Size of Other Communities ......................... 5 Relationship to Other Highway PIans/Programs ...................... 7 II. TRAFFIC ANALySIS................................................ 8 Characteristics of the Street Network ................................8 Traffic Volumes ............................................... 8 Operations Analysis ........................................... 12 III. DRAINAGE CONSIDERATIONS ..................................... 14 Background ................................................. 14 Existing Hydrology. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 Existing Drainage Structures. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 1986 Report Recommended Improvements . . . . . . . . . . . . . . . . . . . . . . . . . . 17 Proposed Improvement Considerations ............................ 17 Improvement Alternatives ...................................... 17 Recommendations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 IV. BRIDGE CONSIDERATIONS ........................................ 22 Overview ................................................... 22 Description of Existing Structure ................................. 22 Bridge Improvement/Replacement Scenarios ........................ 24 Recommendation ............................................. 27 V. ALTERNATIVE INTERCHANGE CONFIGURATIONS .................... 28 Overview ................................................... 28 Diamond Interchange Alternatives ........... . . . . . . . . . . . . . . . . . . . . . 28 Construction Management of Traffic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 Environmental Concerns . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 Bucher. WIIUs & RutlUf. I I I I I I I I I I I I I I I I I I I I MAGNOLIA ROAD/I-135 Break-in-Access Study TABLE OF CONTENTS (Continued) Cost Estimates ............................................... 3] Recommendation ............................................. 32 VI. IMPLEMENTATION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 Overview ................................................... 33 Project Costs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 33 Project Funding .............................................. 34 Construction Schedule ......................................... 34 VII. CONCLUSION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3S Table] Table 2 Table 3 Table 4 Table 5 Table 6 Figure ] Figure 2 Figure 3 Figure 4 APPENDIX Detailed Cost Estimates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 LIST OF TABLES Distances to and Size of Other Communities ......................... 6 Intersection Level-of-Service .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ]3 Summary of Peak Discharges .................................... ]6 Load Rating Analysis Summary .............. . . . . . . . . . . . . . . . . . . . . 23 Project Alternative Cost Summary ................................ 32 Project Funding .............................................. 34 LIST OF FIGURES Study Area .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Projected Construction Year (]996) Volumes. . . . . . . . . . . . . . . . . . . . . . . .. ]0 Projected Design Year (20]6) Volumes ............................. ]] Two-Lane Bridge Alternative .................................... 30 Bucher, WflUs & Ratlw" . U I II I I I I I I I I I I I I I I !~ I I MAGNOLIA ROAD/I-135 Break-in-Access Study I. INTRODUCTION This break-in-access study has been prepared in order to describe the associated benefits and costs of constructing an interchange at Magnolia Road and 1-135. This study has been conducted as per guidelines prepared by the Federal Highway Administration governing justification for additional access points to the Federal Interstate Highway System. The purpose of this report is to describe the addition of an interchange on 1-135 at Magnolia Road. Salina currently has two access points on 1-70 at Ohio Street and Ninth Street, and three access points on 1-135, at State Street, Crawford Street, and Schilling Road. Presently, a two-lane bridge carries Magnolia Road traffic over 1-135 but no access to or from the interstate is available. The alternatives discussed in this report consider a conventional diamond interchange and consider both modifications to the existing bridge and new bridge alternatives. This report discusses the economic development benefits estimated to be derived from the construction of the interchange, as well as other design issues such as relationship to other planned improvements, existing and projected traffic volumes, and projected costs. Study Area The proposed Magnolia Road and 1-135 Interchange is located approximately one mile north of the Schilling Road and 1-135 Interchange and two miles south of the Crawford Street and 1-135 Interchange. The Schilling Road Interchange serves the industrial areas located near the airport and south of Schilling Road. It also serves a large commercial district located along Ninth Street. The Crawford Street Interchange serves businesses located on Broadway as well as some businesses localized around the interchange. The downtown area is served mainly by the State Street and 1-135 Interchange and the Ninth Street and 1-70 Interchange. The proposed interchange location is shown in Figure 1. Bucher, WfUis & RatlUT. 1 II II II I I I I I I I I I I I I I I I I Study Area ~ ~ \ '\ /.--J r----; .." .. ~.,,~"="}.. '~\ '\;-- ('\\ I \ \ r'". ('<,,,-'" , ~ l/=F=- "'j ! i I / I ~~ I ~' I .~. j , \...,/ ;. ~- // - -. ... I _~ I G ........ -- j i I i I I I -- ~ -- ..- ! , , , , , " J -- ~ f I . -, Magnolia Interchange Break-In-Access Study - BUOtR. WW5 . IAlUI' ....... ___ I lUfHllS . MOtftCTI Figure 1 I I I I I I I I I I I I I I I I I I I MAGNOLIA ROAD/I-13S Break-in-Access Study Pwpose of the Project The Magnolia Road Interchange would serve a number of accessibility and economic needs. The purpose of the proposed Magnolia Road and 1-135 Interchange is defined in the following paragraphs. 1. The interchange would improve access to existing retail development. A commercial corridor has developed along South Ninth Street. Two retail malls are located at South Ninth Street and Magnolia Road. The two malls are the Mid-State Mall and the Central Mall which have a combined retail space of 630,000 square feet. Joining the 56 mall tenants, another 44 free-standing retail and service businesses exist along this stretch of Ninth Street, making this area the largest concentration of retail shopping within both the City of Salina and north-central Kansas. Sears built a new department store at the Central Mall, becoming the third department store, joining Dillard's and Penney's. In addition, Sutherland's recently opened at the Mid-State Mall. Approximately 18 percent of the County's retail employees work in the Ninth Street and Magnolia Road shopping area. Over the past five years, the center of retail activity within Salina has shifted to the Ninth Street and Magnolia Road shopping area. Since 1985, this area has seen the construction of the 330,OOO-sq. ft. Central Mall, a 65,ooo..sq. ft. grocery store, a 38,000-sq. ft. strip center known as the Galaxy Shops, and a 114,500-sq. it. Wal-Mart. A new 134,900-sq. ft. Sam's just opened across the street from Wal-Mart. A site plan has been approved for a new Target Store near Schilling Road with a square footage of 89,500. In addition, several retail stores and restaurants are planned on outparcels around these developments. The result has been a growth in both retail sales and the number of retail jobs in the impact area. Although some local retailers have shifted their locations to this area, most of the retail outlets are new businesses in Salina and have resulted in the creation of new retail jobs. 2. The interchange would improve access to existing industrial development An indus- trial corridor has developed along Centennial Road in the southwest portion of the Salina urban area. The proposed interchange at Magnolia Road and 1-135 would directly access this area. Bucher, wm.. & RClt1U1' - 3 I I I I I I I I I II II I I I I I I I I MAGNOLIA ROAD/I-135 Break-in-Access Study A major concentration of business is found in the Airport Industrial Center located one mile west of 1-135. Utilizing land and buildings formerly occupied by Schilling Air Force Base, which was closed in 1968, some 50 manufacturing, distribution, and construction firms now exist. The area is also home to the Kansas State University-Salina College of Technology. Based on figures from the U.S. Census Bureau's County Business Patterns, 46 percent of the County's manufacturing jobs are concentrated in the Airport Industrial Center. In addition to retail jobs; much of the growth in Salina's industrial employment over the past five years has occurred in the Airport Industrial Center. Three of the ten largest employers in Salina are located in the Airport Industrial Center, and employment in this area accounts for approximately ten percent of the total Salina work force. Of the approximately 50 businesses located in the Airport Industrial Center, 18 of those have located their present place of business within the past five years. In a survey of these businesses, 62 percent of the responding businesses reported increases in their business volume over the past five years. The economic growth experienced by the impact area has resulted in the following employment eains over the past five vears: Total number of new jobs created: ................................. 1,115 Number of new jobs that resulted from local firms expanding: . . . . . . . . . . . . 395 Number of new jobs that were the result of firms starting or locating in the area: 720 The types of industries and the jobs created are as follows: Retail and Service Businesses: ...................................... 610 ~anufacturing/Transportation: ..... ...............................433 Education/Training/Rehabilitation: ....................... ...........72 3. Construction of the Magnolia Road and 1-135 Interchange would support new development activity. The City of Salina's Comprehensive Plan indicates continued commercial and light industrial development west of 1-135. Retail activity is also designated for further development along the South Ninth Street Corridor. The ~agnolia Road and 1-135 Interchange project is expected to generate additional economic activity in several major ways: Bucher, WfWs & RatllU' 4 I I I I I I I I I I I I I I I I I I I MAGNOLIA ROADII-135 Break-in-Access Study . Expansion of retail sales and employment among existing retail and service businesses located in the Ninth Street and Magnolia Road shopping area; . Attraction of additional retail and service firms to sites in close proximity to the proposed interchange; and . Expansion of existing firms and creation of new businesses in the Airport Industrial Center. 4. Not constructing the Magnolia Road and 1-135 Interchange would require improvement of a section of Schilling Road between Virginia and Centennial Boulevard. This section of road is two lanes wide without paved shoulders. Traffic forecasts prepared for the Salina Comprehensive Plan indicate that Schilling Road would need to be widened to four lanes if the Magnolia Road Interchange is not constructed. The Schilling Road bridge over Dry Creek is included in the KOOT Five Year Construction Program for fiscal year 1996, providing an estimated $500,000 in funds. This project would include replacing and widening the bridge over Dry Creek. This project is 0.6 miles in length and the cost of construction of a four-lane bridge and roadway with contingencies is estimated at $1,860,000. The cost of reconstructing Schilling Road as a two-lane improvement with bridge replacement and contingencies is estimated at $1,120,000. Thus, constructing the Magnolia Road and 1-135 Interchange would save the City of Salina $740,000 to improve Schilling Road. 5. The Intermodal Surface Transportation Efficiency Act (ISTEA) requires that freight movement be given greater focus than in the past. Two of the 15 factors to be considered in forming a long-range transportation planning process under ISTEA are limited to freight movement. They are access to airports and ports and methods to enhance the efficient movement of freight. The Magnolia Road Interchange will be consistent with these two objectives. It will both improve truck access to the Salina Airport as well as improve freight movement to and from the Airport Industrial Center. The interstate access at Magnolia would reduce the need to use Schilling Road which travels through a residential area and a school crossing zone. Distances to and Size of Other Communities Salina is the largest community in Saline County. The closest cities of any size are Hutchinson (39,000), which is approximately 60 miles to the south, and Manhattan (38,000), which is approximately 70 miles to the east on 1-70. The smaller cities of Newton (17,000) and Junction Bucher. Willis & RCltliU - 6 I I I I I I I I I I I I I I I I I I I MAGNOLIA ROAD/I-135 Break-in-Access Study City (21,000) are approximately 60 miles and 50 miles away, respectively. Newton is located to the south on 1-135, while Junction City is located to the east on 1-70. To the west, the closest city over 10,000 is Hays (18,000) which is 100 miles distant on 1-70. The closest city over 10,000 to the north is Hastings, Nebraska (23,000) which is approximately 130 miles distant on U.S. 81. These and other cities, their population and distance from Salina are listed in Table 1. Table 1 DISTANCES TO AND SIZE OF OTHER COMMUNITIES Population Miles to 1-135 Lindsbo1"l!: 3,()76 16 McPherson 12,422 37 Newton 16,700 62 Hutchinson 39,308 63 Wichita 304,011 90 U.8.81 MinneaDolis 1,983 18 Concordia 6,167 52 Hastinl!;s, NE 23,000 130 1-70 Abilene 6,242 27 Junction City 20,604 48 Manhattan 37,712 68 Topeka 119,883 112 Lawrence 65,608 141 Kansas City (metro) 1,500,000 177 Havs 17,767 100 Colby 5,396 205 Good land 4,983 238 Great Bend 15,427 76 Denver, CO (metro) 1,600,000 420 Bucher, Willis & Rcltqq - 6 I I I I I I I I I I I I I I I I I I I MAGNOLIA ROAD/I-135 Break-in-Access Study Relationship to Other Highway PlanslPrograms The subject of a Magnolia Road Interchange has been an issue of discussion for several years within the City. The 1987 Maior Street and 1-135 Interchan2e Improvement Study in Southern Part of Salina determined an interchange at Magnolia would improve access to the Central Mall, and reduce traffic at the Schilling Road Interchange. The study also considered removal of the Schilling Road and Ninth Street slip ramps. Reconstruction of the Schilling Road and 1-135 interchange is currently under construction. A 1989 Economic Imoact Report of a proposed Magnolia interchange, completed by Bucher, Willis & Ratliff, listed possible economic benefits associated with the Magnolia and 1-135 Interchange. The Salina Comprehensive Plan. prepared by Trkla, Pettigrew, Allen and Payne (TPAP) and Bucher, Willis & Ratliff completed in 1992, recommended the construction of the interchange to reduce volumes on Ninth Street between Magnolia Road and Schilling Road, and to reduce the need to widen Schilling Road to four lanes west of 1-135. The Magnolia Road Interchange was included in the Salina area's Long-Range Transportation Plan. Bucher, 'Willis & Rut1(U. 7 I I I I I I I I I I I I I I I I I I I MAGNOLIA ROAD/I-135 Break-in-Access Study IL TRAFFIC ANALYSIS This section describes the field investigations conducted and the evaluation of existing traffic conditions in the Magnolia Road and 1-135 vicinity. The interpretation of data compiled in this section provides the basis for the preparation of the conceptual engineering design alternatives. The section is divided into the following areas: . Characteristics of the Street Network - describes the street and roadway layouts and traffic operations within the study area; · Traffic Volumes. describes the current traffic volumes in the study area including daily, a.m. peak and p.m. peak volumes; and · Operations Analysis - describes the level-of-service of both the construction year (1996) and the design year (2016) of the Magnolia Road and 1-135 Interchange and the Magnolia Road and Ninth Street intersection. Characteristics of the Street Network The portion of Magnolia Road under study extends from 1-135 to Ninth Street. In this area, Magnolia Road is a five-lane arterial that tapers to two lanes at the bridge over 1-135. Lane widths on Magnolia Road average 12 feet. Road edge consists of curb and gutter through the five-lane section. The existing bridge is 24 feet wide. Two lanes with a ditch section are provided between the bridge and Centennial Road. A guardrail is provided on the north side due to a steep slope. Pavement conditions are generally adequate on Magnolia Road. Lane markings are also adequate. Currently, the intersection of Magnolia Road and Ninth Street is signal controlled. This four-way intersection consists of a signal with separate phases for left turns on both Magnolia Road and Ninth Street. The speecllimit on Magnolia Road is currently posted at 30 miles per hour. Traffic Volumes To assess the existing traffic demand on Magnolia Road, traffic counts for the intersection of Magnolia Road and Ninth Street were reviewed. Daily counts on Magnolia Road were also reviewed. The 1991 counts indicated that daily traffic volumes on Magnolia Road west of Ninth Street in the study area averaged 8,200. Daily traffic volumes west of the bridge over 1-135 were Bucher, WIWs & Ratlur. 8 I I I I I I I I I I I I I I I I I I I MAGNOLIA ROAD/I-135 Break-in-Access Study 3,500. Recent traffic counts for 1-135 indicated daily traffic volumes of 9,750 between Schilling Road and Crawford Street. Estimates of future traffic use provide one measurement of the need for a street improvement. Traffic forecasts are prepared to indicate how much traffic would be expected to utilize a specific street improvement, if it were constructed. This information is often used to evaluate and quantify the benefits derived from a particular project. Traffic forecasts are also used by traffic engineers to determine specific roadway design characteristics, such as the type of roadway, the number of lanes, the need for turn lanes, turn bay lengths, signal locations, and other intersection treatments. Future traffic projections for a roadway are often estimated using a transportation simulation model. Transportation simulation models, like other simulation models, use mathematical relationships to predict likely future outcomes. Transportation simulation models predict traffic volumes on the street system by relating the type and intensity of land use development to potential trip making. The traffic generation associated with each land use is assigned to the street network. In the model, traffic is assigned to the street network on routes based upon street capacity and travel time. Transportation simulation models are often used to analyze alternative scenarios by adjusting the land use inputs or by changing the street system characteristics. The traffic model was modified to reflect a diamond configuration at Magnolia Road and 1-135. The traffic forecasts reflect future land use projections developed by the City of Salina as part of the comprehensive planning process. Traffic projections for the Magnolia Road and I-135lnterchange were prepared by the Kansas Department of Transportation (KDOT) for both the construction year (1996) and the design year (2016). The peak hour turning movements produced by KDOT are for simultaneous peaks. The simultaneous peak represents the peak movements occurring throughout the day in one peak hour. The simultaneous peak hour turning movements were calculated using a design hour volume of 11 percent and a 60 percent directional distribution. The simultaneous peaks were separated into a.m. and p.m. peak hour movements by the consultant, in order to provide a representation of predicted travel conditions during peak travel periods. The resulting projected 1996 daily and peak hour volumes are shown in Figure 2. Similarly, design year volumes for 2016 are indicated in Figure 3. The simultaneous peak volumes are the highest volumes number indicated for a given turning movement. Bucher, Willis & Ratlw" - 9 I I Projected Construction Year (1996) Volumes I DAILY VOLUMES '& ~jtL .1- I _ 2IlO oJ rn I ! I 'L Magnolia _ ..... ~ I ~ .... I .... -+ I ~ II , ~ I I ~..J , '+\ L...., . .- 1IOD ---./ '-_ 1IDO _ 4OIlO I 11fl I PEAK HOUR VOLUMES I ~jtL oJ I rn = :! I L Magnolia I I I I liil ~ I DOO P.M. Plak How ProjoctlDn II , I I cooo) AM. Peak How Projocllan , I Magnolia Interchange __WWl.IA'Rft' ....... I ....... . MDftlCTI I Break-in-Access Study Figure 2 I I I I I I I I I I 'I I I I I I I I I I Projected Design Year (2016) Volumes DAILY VOLUMES 'a ~ +- .... Magno6a +- .... \fJ ~ ....- .... - PEAK HOUR VOLUMES I '-- 1DlIO-' L01IlO 17IlO_ 11(1 I I I 000 PM Peak Hour ProJecllon I I (000) AM Peak Hour Projecllon I , Magnolia Interchange Break-In-Access Study ... en i ! ~ -- -- I +.,. IRlll ~.J * U 110O J ',-- 1110O 110O -+ +- AOO .... =t c 1300 lit if \. IIIII / ... en -= ! L ~ - _ WIII5 61lA1\If .... ...... . I'UiIIl.-s . MOmICIJ Figure 3 I I I I I I I I I I I I I I I I I I I MAGNOLIA ROAD/I-135 Break-in-Access Study Operations Analysis The assessment of traffic impacts within the corridor is described in terms of level-of-service. The level-of-service calculations were prepared for both stop control and signalized intersection operation for the interchange. The ca1culations were based upon the projected intersection turning movements, traffic volumes, lane geometries and traffic signal timings for both the year 1996 and the year 2016 scenarios. The traffic operations analysis for the Magnolia Road Interchange ramps and for the Ninth Street and Magnolia Road intersection is summarized in Table 2. This analysis was performed in order to determine the geometries required to ensure an adequate level-of-service at the time the interchange is completed and throughout the 2O-year design period. The analysis was performed for projected year 1996 and year 2016 volumes. The results are presented based upon both estimated a.m. and p.m. peak hour volumes, as well as the simultaneous peaks procedure used by KDOT for design purposes. Simultaneous peak represents all peak movements during the day in a one-hour period. The results indicate that a three-lane bridge cross section would be desirable. Heavy directional peak left turns at the ramp intersections need to be accommodated by the center left-turn bay. Review of the estimated a.m. and p.m. peak hour information indicates that a satisfactory level- of -service would be provided at the construction year and for the design year. Signalization of the two ramp intersections is shown to approach the peak hour signal warrant. Because warrants may possibly be met upon project completion and because sight distance from the ramps may be limited by the bridge rails, it is recommended that the ramps be considered for signalization as part of the construction of the project. Analysis of the simultaneous peak volumes yielded poorer levels-of-service and greater levels of vehicle delay. Further investigation of projected design year turning movements was conducted in order to determine adequate storage bay length. The Year 2016 traffic forecasts indicate eastbound left turn movement of 132 and a westbound left turn movement of 370. The conceptual design of the left-turn bays reflects adequate turn movement storage. The proposed interchange will have minimal impact to adjacent interchanges and to 1-135 volumes. The adjacent interchange two miles north is at Crawford Street. The adjacent interchange one mile south is at Schilling Road. The impacts at Crawford Street are less than at Schilling Road due to the greater distance from Magnolia Road. The interchange at Magnolia Road would be expected to reduce traffic on each ramp of the north half of the Crawford Street interchange by 100-200 trips per day. Traffic on the south half of the Crawford Street Bucher, Willis & Ratlur. 12 I I I I I I I I I I I II I. I I I I I I MAGNOLIA ROAD/I-13S Break-in-Access Study interchange would increase by approximately 300 trips per day, due to increased travel on 1-135 between Crawford Street and Magnolia Road. Future year ADT on 1-135 was projected in the Salina Comprehensive Plan to be approximately 11,500 ADT between Magnolia Road and Crawford Street, and 17,200 between Schilling Road and Magnolia Road. These volumes could be easily accommodated by a four-lane freeway facility. Daily traffic on the south half of the Schilling Road interchange would decrease by about 1000 vehicles which would be attracted to the Magnolia interchange. Traffic on the each ramp of the north half of the Schilling interchange would increase by approximately 1,500 daily vehicles due to improved local accessibility. 1-135 mainline volumes would also be impacted by the construction of the new interchange. Traffic volumes would increase by approximately 2,500 - 3,500 total for both directions between Schilling Road and Magnolia Road and increase only 1,000 vehicles for both directions between Magnolia Road and Crawford Street. Table 2 INTERSECI10N LEVEL-OF-SERVlCE 1996 2016 AM PM SIMUL- AM PM SIMUL- Signalized PEAK PEAK TANEOUS PEAK PEAK TANEOUS LOS Delay LOS Delay LOS Delay LOS Delay LOS Delay LOS Delay Magnolia/Ninth D 26.3 e 24.0 D 30.5 E 41.6 0 34.1 F 75.5 Existing Bridge 1-135/Magnolia West B 123 e 21.2 F >100 F >100 F >100 F >100 1-135/Magnolia East e 19.2 e 24.6 F 78.0 F 78.0 F >100 F >100 Widened Bridge 1-135/Magnolia West e 15.1 e 20.3 e 21.2 e 21.4 0 33.5 E 46.2 1-135/Magnolia East e 20.8 0 28.5 0 328 0 32.1 F 77.6 F >100 Delay = Average delay per vehlcle In seconds. LOS = LeveJ-of-servlce Bucher, Willis & Rat1(U. 13 I I I I I I I I I I I I I I I I I I I MAGNOLIA ROAD/I-135 Break-in-Access Study Ill. DRAINAGE CONSIDERATIONS The proposed Magnolia Road and 1-135 Interchange will be located within one of the more sensitive and complicated hydraulic drainage systems within the City of Salina and Saline County. The interchange, located at the intersection of Magnolia Road and 1-135, is on the western corporate boundary of the City of Salina. It will cross over the Magnolia Road Ditch both east and west of the interstate and will be approximately one-half mile east of the Dry Creek channel. Both are significant to the drainage in south Salina. The construction area east of 1-135 will be in the City of Salina, and the area west of 1-135 will be in Saline County. Background Much of Salina is located within the broad alluvial flood plain created by the convergence of the Smoky Hill River, Saline River, Mulberry Creek and Dry Creek. Flooding on anyone of these streams has historically caused significant flooding within the City of Salina. Because of the very flat flood plain topography, local intense rainfaII can also create significant localized flooding. The continued reoccurrence of the flooding from the converging streams resulted in the construction of the Salina Levee Protection System in 1961. This levee system includes 14 miles of levee protection as well as channel improvements to the Smoky Hill River, Dry Creek and Mulberry Creek. The levee system does not, however, protect the City from the flooding resulting from the localized heavy rainfaII as occurred in October 1973, April 1974, August- September 1977, and June 1981. Continued development in the southern portion of the City has increased the impervious areas which contributes to the possibility of significant flooding, although the addition of detention ponds has helped to control local runoff. The Dry Creek watershed extends from the northern portion of McPherson County to the confluence with Mulberry Creek at the western City Umit of Salina south of 1-70. The Dry Creek Diversion is one of the flood control projects completed as a part of the 1961 Salina Flood Protection Project and is located near the town of Mentor, three miles south of Salina. This diversion redirected the majority of the runoff from the Dry Creek watershed to the Smoky Hill River at this location. The remaining watershed (approximately 30 square miles) downstream (north) of the Dry Creek Diversion will continue to drain into Mulberry Creek. Magnolia Road Ditch drains into this section of Dry Creek. Dry Creek north of the Dry Creek Diversion drains most of the residential areas in south Salina west of the Union Pacific Railroad tracks and drains much of the eastern portion of the Salina Municipal Airport. Bucher, WfIUs & Rlltl(U - 14 I I I I I I I I I I I I I I I I I I I MAGNOLIA ROAD/I-13S Break-in-Access Study The Magnolia Road Ditch stormwater collection area begins south of Salina near Mentor and runs northerly to Magnolia Road. The purpose of the Magnolia Road Ditch is to collect stormwater runoff from an approximately 28 square mile area and divert this runoff from the Smoky Hill River watershed into the Dry Creek watershed and into Mulberry Creek. The ditch was constructed by the City of Salina to redirect the storm water runoff which would normally flow northerly through the developed sections of Salina before entering the Old Smoky Hill channel. This improvement is to reduce flooding problems in the older developed areas in the City. The proposed interchange would cross over this ditch. The area drained by the Magnolia Road Ditch has very little topographic relief, and extensive areas are included within the Zone AH and Zone AS 1oo-year flood plain as indicated on the FIRM maps prepared by FEMA in 1986. This area has undergone extensive development within the last 10 years with the construction of the Central Mall, Hughes Building Center, Dilloris Supermarket, and strip shopping centers around the Magnolia Road and Ninth Street intersection. The development of this area has been accompanied by the construction of detention basins with flap-gated outlet drainage structures. Existing Hydrology The hydrology in the area of the Magnolia Road Ditch and Dry Creek is extremely complex and has been the subject of numerous studies including the Enltineerin2 Reoort for Selected Draina2e Imorovements in South Salina. Kansas completed by Bucher, Willis & Ratliff in 1986; fu!!!!h Salina Draina2e Studv Enltineerin2 Reoort completed by Wilson & Company Engineers and Architects in 1978; and extensive portions of the Flood Insurance Studv. Citv of Salina. Kansas. Saline Countv prepared for the Federal Emergency Management Agency in February 1986. A summary of the peak discharges calculated by the FlS and the Bucher Willis & Ratliff study in the Magnolia Road Ditch at 1-135 is contained in Table 3. Bucher, WfUfs & alltlUf. 18 I I I I I I I I I I I I I I I I I I I MAGNOLIA ROAD/I-135 Break-in-Access Study Table 3 SUMMARY OF PEAK DISCHARGES (Cubic Feet Per Second, cfs) Study 10- Yr. so- Yr. lOll-Yr. SOO-Yr. Bucher, Willis & Ratliff "Engineering Report 223 297 324 378 of Selected Drainage Improvements in South Salina It Federal Emergency Management Agency 271 390 407 438 Flood Insurance Study The hydrology is more complex because the coincidence of the peak discharges on Dry Creek and on Magnolia Road Ditch cause the Magnolia Road Ditch to flow backwards into the levee protected areas in south Salina as discussed in the above three referenced studies. This back flow actually can divert water from the Dry Creek Channel into the Old Smoky Hill River Channel according to these studies. Additionally, as the surface elevation of water in the Magnolia Road Ditch reaches elevation 1235.7 ft. NGVD, the flap gates from the Central Mall detention basins will not open to permit discharge into the Magnolia Road Ditch, and the additional water will be forced northward into Fourth Street and Wayne Avenue according to the Bucher Willis & Ratliff study. The 5O-year water surface elevation of the flap-gated outlet from the Central Mall is 1237.4 ft. NGVD. Existing Drainage Structures Currently there is a 9-foot by 7-foot by 200-foot reinforced concrete box (RCB) under 1-135 along the north side of Magnolia Road; a 9-foot by 7-foot by 4O-foot RCB located under a farm home driveway and a field entrance; two 16-foot by 14-foot by 3O-foot RCBs under Magnolia Road at Dry Creek; and a 9-foot by 7-foot by nOQ-foot RCB under South Ninth Street. The Magnolia Road Ditch between the above noted structures is an open ditch with generally 3 to 1 side slopes, a la-to IS-foot flat bottom width, and typically is 10 to 15 feet deep. The flow line elevation at the east end of the RCB under Ninth Street is elevation 1230.5 and is 1228.0 at the flow line of the RCB at Dry Creek approximately 1 mile to the west or drops 2.5 feet per mile. There are detention basins located to the north of the Magnolia Road Ditch south of the Dillons Store. There is a drainage detention area south of the trailer park area as well. Bucher, WUUS & Ratl(ff. 16 I I I I I I I I I I I I I I I I I I I MAGNOLIA ROAD/I-13S Break-in-Access Study 1986 Report Recommended Improvements The Bucher, Willis & Ratliff Engineering Report of 1986 recommended enlarging the existing structures by adding two lo-foot by 6-foot RCBs adjacent to the existing 9-foot by 7-foot RCB under 1-135 and the farm entrances. TI1is report also recommends that the existing Magnolia Road Ditch be widened to a 4O-foot wide flat bottom ditch. Additional improvements are recommended throughout the system and particularly to widen and clean the Dry Creek Channel from Republic Avenue to Magnolia Road. These recommended improvements are predicted to lower the 100-year water surface elevation of the Magnolia Road Ditch from 1240.0 at 1-135 to elevation 1237.0 with the associated benefits to the hydraulic system served by the Magnolia Road Ditch. Many, if not most, of the recommended improvements to the hydraulic system have not been completed to date primarily because of the cost required to complete the improvements. It is unknown when or if the proposed improvements will be completed. Proposed Improvement Considerations The proposed interchange improvements from Magnolia Road to 1-135 will need to take the following factors into consideration: 1. The proposed improvements must not reduce existing detention areas without providing alternative detention sites or compensatory improvements in the drainage channel. 2. The proposed improvements should not impair the hydraulics of the Magnolia Road Ditch and thereby create additional flooding in the existing flood plain. 3. Fill for the interchange ramps will be located within the existing 100-year flood plain. Care must be exercised to insure that the existing flood elevation is not increased and existing drainage ways are not further constricted. Improvement Alternatives The hydraulic improvements recommended by the earlier reports for the Magnolia Road Ditch and the Dry Creek Channel improvements have not been completed because of lack of funds. Bucher. WlUIs & R4tlUJ' . 17 I I I I I I I I I I I I I I I I I I I MAGNOLIA ROAD/I-135 Break-in-Access Study If and when these improvements will be completed influences the proposed improvement alternatives. Three drainage scenarios identified include the following: 1. Assume that the proposed improvements to the Magnolia Road Ditch and to the Dry Creek Channel will not be cost effective or will not be funded. Therefore, the alternative will be to build the interchange based on the hydraulics of the existing RCBs under 1-135 and the farm and field entrances (i.e., build 9-foot by 7-foot RCBs under the two ramps). 2. Assume that the proposed improvements as recommended by the 1986 report will be completed at some time in the future, but that this project will include funding only to build the necessary structures under the southbound off ramp and the northbound on ramp, (i.e., three lo-foot by 7-foot RCBs under each of the ramps) and widen the ditch between 1-135 and the ramps to a 4O-foot wide flat bottom ditch. 3. Allocate the funds to complete the improvements to the Magnolia Road Ditch drainage system from the interchange on the west to the Dry Creek Channel and complete these improvements as a portion of this interchange construction project. These alternatives were evaluated based on their advantages, disadvantages and costs, and are described below: Drainaee Scenario 1 - Assumes No Present or Future Drainaee Improvements. This alternative would construct a 9-foot by7-foot RCB under each of the two ramps. This structure will have the same hydraulic capacity as the structure under 1-135 and under the farm home and field entrances. Advantages: 1) It is the least expensive alternative. 2) There is no disruption to the land owners located downstream from the proposed interchange. 3) It provides less disruption to traffic on 1-135 than the other alternatives. Bucher, WillIs & RcatIUr. 18 I I I I I I I I I I I I I I I I I I I MAGNOLIA ROAD/I-13S Break-in-Access Study 4) No additiona11and purchase would be required. Disadvantages: 1) The existing drainage problems are not addressed. 2) Future drainage improvements would be much more expensive and/or have limited improvement capability. Construction Cost: $203,000 Drainal!:e Scenario 2 - Construct Structures Under Ramus Sized for Future Draina~e Imorovements. This alternate would construct three 1D-foot by 7-foot RCBs under each of the two ramps and grade a 4D-foot wide flat bottom ditch between the ramps and the existing 9-foot by 7-foot RCB under 1-135. Advantages: 1) This will make it easier to complete the proposed Magnolia Road Ditch improvements in the future. 2) This is a cheaper alternative than the full drainage system improvements, described in Drainage Scenario 3. 3) This scenario will provide some runoff detention and a buffer area between the ramps which may slightly reduce the flooding potential. This advantage is expected to be minimal. Disadvantages: 1) The existing drainage problems will not be fully addressed. 2) H the drainage system improvements are not completed in the future, the additional cost associated with these improvements would be greatly wasted. Bucfler. WUUs & RatlUT. 19 I I I I I I I I I I I I I I I I I I I MAGNOLIA ROAD/I-135 Break-in-Access Study 3) More expensive than Scenario 1. Construction Cost: $564,000 Drainal!:e Scenario 3 - Comolete the Storm Drainal!:e Imorovements for Mae:nolia Road Ditch and Drv Creek Channel. This alternative would construct the storm drainage improvements outlined in the Stage II Plan of the 1986 Enl!:ineerinl!: Report for Selected Drainal!:e Improvements in South Salina, Kansas for the improvements downstream of the east ramp area of the Magnolia Road Ditch and Dry Creek Channel. This project will not construct improvements outlined for the area east of the driveway to the commercial center located east of the northbound on ramp or the areas south of Magnolia Road. The proposed improvements would include constructing a triple lo-foot by 7-foot RCB under each ramp; adding double lo-foot by 7-foot to the existing 9-foot by 7-foot RCB culvert barrels and modifying the wingwalls on the existing RCB culverts already under 1-135 and the farm home and field entrances; widening the existing Magnolia Road Ditch to a 4O-foot wide flat bottom ditch; and widening and cleaning up improvements to the Dry Creek Channel as recommended in the Engineering Report in the area between Republic Avenue and Magnolia Road. Advantages: 1) These improvements are a part of the total plan for improving the drainage in south Salina and will provide a significate benefit to flood prevention for the region. 2) The area east of 1-135 which is now partially in the l00-year flood plain will be significantly reduced in size. This would permit additional development to occur in the area. 3) Combining this work with the other interchange work may provide some of the required interchange embankment construction material. H included in the total package, the total project costs may be less than if the projects are constructed separately. Bucher, Willis & Rutl(U - 20 I I I I I I I I I I I I I I I I I I I MAGNOLIA ROAD/I-135 Break-in-Access Study 4) It is possible that funds may be available for the total project which would not be available if sought separately. Disadvantages: 1) This is the most costly alternative. 2) Providing interstate access at this point will benefit all of Salina. However, the benefits gained by the drainage improvements will primarily benefit the southwest area of the City even though the entire City will bear the cost. 3) This will require the purchase of additional land. Construction Cost: $1,590,000 Right-of-Way Cost $ 33,000 Recommendations Drainage Scenario 1 is the least expensive option. Although it precludes future drainage improvements which may be beneficial, the City is considering other drainage improvements which have even greater flood reduction benefits than the improvements described in Drainage Scenarios 2 and 3. These other improvements are primarily diversion of runoff from the drainage basin before it reaches the sit.e Those improvements would have no direct relationship to the Magnolia interchange project. Therefore, Drainage Scenario 1 is recommended as the preferred option. If the City decides to keep the option open of future drainage improvements along the Magnolia Road Ditch, then Scenario 2 would provide that flexibility at an additional cost of around $361,000. Scenario 3 would provide an ultimate solution, but at a cost beyond what the City has available at this time. Bucher, WiDfs & RAtIUJ" . 21 II I I I II I I I I I I I I I II I I II I MAGNOLIA ROAD/I-135 Break-in-Access Study IV. BRIDGE CONSIDERATIONS Overview A significant study consideration is whether to utilize the existing 1-135 overpass, widen the existing overpass, or construct a new overpass as part of the new Magnolia Road Interchange. This section addresses this issue and includes a review of the existing vertical and horizontal alignment, a load rating analysis of the existing structure, rehabilitation alternates and a replacement alternate. Description of Existing Structure The existing structure was built in 1963 as part of the original 1-135 construction. It carries Magnolia Road (FAD 4804) over the interstate and connects with Ninth Street to the east and Centennial Road to the west. The structure is a 234-foot, 6-inch long continuous reinforced concrete box girder bridge. As-built plans show a design loading of Hl5-44 based on the 1957 A.A.5.H.O. specifications. It has spans of 42 feet-74 feet-74 feet-42 feet and a 24-foot wide roadway. The superstructure is supported on reinforced concrete single column integral cap beam piers and reinforced concrete abutments. 10BP42 steel piles support both the abutments and the piers. The piles are driven to bearing in shale. The overpass was aligned on a 10OO-foot long crest vertical curve with approach grades of 4.45 percent and 4.83 percent. The K value and stopping site distance were determined to be 108 and 378 feet, respectively. These values correspond to a design speed between 40 and 45 miles per hour. Vertical clearance under the structure is 16 feet, 6 inches, which meets the current standards. The horizontal clearance is 28 feet from edge of pavement to the face of the median pier and 12 feet, 4 inches to the face of the outside piers. All of the piers are within the clear zone and require a barrier between the edge of shoulder and the pier. The horizontal clearance for the outside piers is significantly below the desired clearance of 34 feet. A field inspection of the existing structure was performed. The structure was found to be in good condition. A 1/2-inch thick asphalt overlay covers most of the deck. A technique for inspecting a large deck is to chain drag it using a series of short weight chains. The deck was chain dragged to determine areas of delamination. Delamination occurs when the buildup of rust on the reinforcing bars in the deck creates sufficient internill force to crack the deck concrete in the plane of the reinforcing steel. Eventually, these delaminated areas will separate from the deck creating a spall. A spalled area is a circular or oval depression in concrete. Approximately ten percent of the deck was found to be delaminated. Light concrete cracking was found Bucher, WlUfs & RatlUr - 22 I I I I I I I I I I I I I I I I I I I MAGNOLIA ROAD/I-135 Break-in-Access Study throughout the rest of the superstructure and substructure, but there were no visible signs of overstress or significant deterioration. A load rating analysis was performed on the structure using the strength design method. A load rating is used to determine the capacity of a bridge to carry loads. The results of the analysis are summarized in Table 4. Table 4 LOAD RATING ANALYSIS SUMMARY AASHrO Truck Type Weight Inventory Operating Rating Rating H2O 20 Tons 16 Tons 26 Tons Type 3 25 Tons 19 Tons 32 Tons HS20 36 tons 21 Tons 36 Tons (HS 11.7) (H520) Type 3-52 36 Tons 27 Tons 45 Tons Type 3-3 40 Tons 32 Tons 54 Tons The exterior girders controlled the ratings. An additional dead load was added to the analysis for a silica fume concrete wearing surface, assuming the top 3/4-inch of the deck would be milled off and a I I/2-inch thick wearing surface would be constructed. The dead load is the static load due to the structure itself. A silica fume concrete wearing surface consists of a highly impermeable concrete mixture. This results in an additional dead load of approximately ten pounds per square foot for the 3/4-inch increase in deck thickness resulting from the new wearing surface. Load posting. of the structure is not required provided that the Operating Rating exceeds the weight of the designated truck weight. Based on the above ratings, load posting of this structure would not be required. For alternatives involving major rehabilitation such as widening the structure, it is preferred that the Inventory Rating of the structure exceed the designated truck weight. The inventory ratings for this structure are below the designated truck weights for all truck types. Consequently, the use of a portion of the existing structure in a major rehabilitation alternative is undesirable. A cost effective method for increasing the load capacity of the existing structure was not identified. For alternatives involving the construction of new structures or the new portions of widened structures, the current criteria requires that the structure be designed for HS-25 loading. Bucher, Willis & RlltlU1 . 23 I I I I I I I I I , I I I I I I I I I I MAGNOLIA ROADII-135 Break-in-Access Study Bridge ImprovementJReplacement Scenarios Three bridge improvement/replacement scenarios were studied. The three bridge scenarios include the following: 1. Rehabilitate the existing bridge. This would include milling off 3/4-inch of the existing concrete deck, removing and replacing any deteriorated concrete, and constructing a 1 1/2-inch thick silica fume concrete wearing surface. Additionally, the existing bridge handrail would be modified. The existing structure has a roadway width of 24 feet. This structure meets the minimum requirements for deck width and loading to remain in place for a two-lane approach. Although this structure meets these minimum requirements, it is questionable whether continued use of the structure would provide an effective solution .due to the high traffic volumes and the four or five-lane approach to the east. The rate of deterioration on the existing structure will accelerate when the structure is exposed to higher traffic volumes and increased application of deicing chemicals following the completion of the interchange. This would shorten the service life of the structure. Replacement of the structure within ten years following the completion of interchange is probable due to structural condition and functional obsolescence. Prior to the consideration of this alternative, discussions should formally be conducted between the City of Salina and the KDOT to determine the financial responsibility for the replacement of the existing structure at a future date. It is possible that the approval of this alternative would be contingent upon the participation of the City of Salina in future . replacement of the structure. 2. Widen the existing structure by constructing additional width of roadway on each side matching the existing span lengths. The rail and curb would be removed, the deck milled, deteriorated concrete removed and replaced, and a silica fume concrete wearing surface placed. Reinforced concrete piers and abutments would be constructed next to the existing substructure units. The concrete deck would be supported on 36-inch deep steel rolled I-beam girders. The proposed roadway width would be 48 feet, curb to curb. This would accommodate two 12-foot wide driving lanes, one 12-foot wide turning lane, a 6-foot wide median with one-foot offsets, and 2-foot wide shy distance to the rails. This structure would require two longitudinal joints due to the differential deflection between the existing concrete structure and the proposed steel additions. These joints inherently suffer from maintenance problems. In addition, the existing structure in the Bucher. Wiuts & Ratlur. 24 I I I I I I I I I I I I I I I I I I I MAGNOLIA ROAD/I-135 Break-in-Access Study center would have a much shorter remaining service life than the new steel additions. Also as noted in the discussion of the load ratings, the inventory ratings of the existing structure do not meet the current desirable criteria. Due to these limitations, this alternative is not recommended for further consideration. 3. Replacing the existing overpass with a new structure. As in Scenario 2, the proposed roadway width is 48 feet, curb to curb. This scenario would provide two 12-foot wide driving lanes, one 12-foot wide turning lane, one 6-foot wide median with one-foot offsets, and 2-foot wide shy distance to the rails. The deck would be supported on steel welded plate haunched girders. Prestressed concrete girder construction was also considered, but the effect of raising the grade on Magnolia Road to accommodate thicker members expanded the limits and costs of the project, making the steel welded plate haunched girder construction more attractive overall. Two spans would be constructed at equa11engths of 135 feet for a total structure length of approximately 275 feet. This configuration would not require a pier to be located within the outside roadway clear distance. The outside roadway clear distance provided included a 2 feet deep ditch, 6 to 1 side slopes, 8 feet wide bottom and 4 to 1 back slopes. Additionally, the existing Magnolia Road crown grade should not need to be raised significantly. The substructure would consist of a single pier in the median and abutments on each end. These alternatives were evaluated based on their advantages, disadvantages and costs, and are described below: Bridl!:e Scenario I-Rehabilitate Existinl!: Bridl!:e. Advantages: 1. It is the least expensive alternative. Disadvantages: 1. A two-lane bridge would not provide an adequate traffic level-of-service at the east ramps based upon analysis of design year volumes. 2. The existing bridge does not meet current standards for a new structure. 3. Over half of the existing bridge's service life has been utilized and the remaining service life, based on an accelerated deterioration rate, may not justify repairs. Bucher, WfUfs & RClaUT. 25 II I I I I I I I I I I I I I I I I I I MAGNOLIA ROAD/I-135 Break-in-Access Study 4. The existing structure will eventually need to be replaced at a significant cost to the public. Approval of this alternative may be contingent upon the City's participation in the replacement cost. Construction Costs: $113,000 Bride:e Scenario 2 - Widen the Existine: Structure. (Not recommended for further consideration) Advantages: 1. The bridge would accommodate projected traffic demand. 2. It is less expensive than Bridge Scenario 3. Disadvantages: 1. The bridge would be constructed of different materials at different times. 2. Longitudinal joints will increase maintenance costs. 3. The existing portion of the structure would need to be replaced sooner than the widened sections. 4. The existing bridge does not meet the current desirable criteria for load capacity. Construction Cost: $536,000 Bride:e Scenario 3 - Reolace the Existine: Overpass with New Structure. Advantages: 1. The bridge would accommodate projected traffic demands. 2 The bridge would meet all the current standards for a new structure. 3. The bridge would have a significantly greater service life with reduced maintenance costs over that life. Bucher, WfUfs & RutlU1' - 26 I I I I I I I I I I I I I I I I I I I MAGNOLIA ROAD/I-135 Break-in-Access Study Disadvantages: 1. The initial construction cost for this bridge scenario is higher than the other scenarios. Construction Cost: $929,000 Recommendation Bridge Scenario 3 should be selected for the proposed interchange. This alternate would provide adequate roadway capacity for the projected future traffic demands. Unlike the first two scenarios, a completely new structure would provide an extended service period in which little maintenance or rehabilitation would be required. Bucher, walts & RlltlW'. 27 I I I I I I I I I I I I I I I I I I I MAGNOLIA ROAD/I-135 Break-in-Access Study V. ALTERNATIVE INTERCHANGE CONFIGURATIONS Overview A number of ramp configurations were considered in developing alternatives for interchange construction. The most common types of interchanges are cloverleaf, diamond and directional. A cloverleaf interchange provides loop ramps for some or all of the left turns. A full cloverleaf has ramps for two turning movements in each quadrant. A diamond provides a single one-way ramp in each quadrant and left'turns are made directly on the minor roadway. A directional interchange generally has more than one highway grade separation and provides direct or semi- direct connections for the major left turn movements. The appropriate type of interchange configuration for any location is dependent on several factors, including traffic demand, physical constraints in one or more quadrants, and the number and direction of intersecting highways. Future traffic demands at the 1-135 and Magnolia Road Interchange are such that a diamond interchange would be adequate. The advantages of a diamond interchange as opposed to other configurations are that a diamond requires less land and costs less to construct. The only reason to consider a partial cloverleaf interchange at Magnolia Road and 1-135 would be if physical constraints were such that one quadrant of the interchange would be unsuitable or undesirable for ramp construction. Complete preservation of the mobile home park in the northeast quadrant of the interchange would require construction of a loop ramp in the southeast quadrant in order to provide northbound access onto 1-135. The southeast quadrant does not provide sufficient room for construction of an adequate loop ramp without removal of a portion of the adjacent shopping center. The cost of relocating several mobile homes would be less than the shopping center demolition. Therefore, incorporation of a loop ramp offers no advantage and would likely increase costs. Consequently, only a diamond configuration is recommended for further consideration. Diamond Interchange Alternatives With a diamond interchange configuration, there are only two interchange alternatives. The alternatives include a two-lane bridge and a three-lane bridge as described in Bridge Scenarios 1 and 3. The ramp construction with a new bridge would require additional grading compared to the existing bridge scenario. Both north ramps would require reinforced concrete box construction under the ramps to allow passage of flood waters, as described in the hydraulic- hydrologic construction section. Construction of the northeast ramp would require relocation of 16 mobile homes. A parcel of land immediately to the east of the mobile home park is mostly vacant and is being developed with mobile homes and could possibly accommodate the relocations. Bucher, WiUis & RCltlUT - 28 I I I I I I I I I I I I I I I I I I I MAGNOLIA ROAD/I-135 Break-in-Access Study The improvement of Magnolia Road will differ between the two bridge scenarios. Under Bridge Scenario 1 where the existing bridge is utilized, Magnolia Road would remain as a two-lane road from west of 1-135 to the east ramps. Magnolia Road would be widened to four lanes east of the ramps, tapering to five lanes to match the existing street width at the east entrance to the shopping center. Under Bridge Scenario 3, Magnolia Road would taper from two lanes west of the interchange to three lanes at the west ramps. Figure 4 illustrates this alternative. This three-lane section would continue across the bridge to the east ramps. Between the east ramps and the shopping center entrance, Magnolia Road would be a five-lane section. In both alternatives, one additional eastbound lane would begin at the east ramps and continue east, and one additional westbound lane from the east would terminate at the east ramps. The termination of the ramps provides a convenient transition from two through lanes west of the interchange to the four existing through lanes east of the interchange, without an excessive amount of lane tapers. This configuration does result in an abrupt lane drop for the outside westbound lane. The details for the bridge rail termination and the safety treatments for the berm slopes most be carefully evaluated during the design phase. A new bridge would require a change of vertical alignment on Magnolia Road, which would increase the length of the project and require additional grading. A retaining wall would need to be constructed along the south side of Magnolia Road east of 1-135. The wall would be set 10 feet behind the back of the curb and would extend above grade with a safety face to prevent vehicles or pedestrians from accidentially going over the wall. The retaining wall would prevent encroachment on to the north end of the shopping center parking lot Additionally, the driveway located furthest west would be closed. The design speed for the Magnolia Road improvement would be set at 40 mph. Even though vehicles approaching from the rural conditions to the west might be traveling greater than 40 mph, the ramps on the west side of 1-135 would have sufficient sight distance to the west for the greater speeds, and sight distance for the east ramps would be based on a higher design speed criteria of 60 mph used for the bridge only. For each of the two viable structura1 scenarios, the same three drainage scenarios would be possible as presented in the drainage considerations, for a total of six unique improvement alternatives. Bucher, Willis & RatItU. 29 . . i.. ,I I I I I I I I I I I I I I I I I Three-Lane Bridge Alternative ~-.7,l;'(.- --- . \ le':',' k~ill ,. . rrAil , I ,,!f!JV I , I I - -l I I , I I , I , I I , I , I I I I I I I , I Magnolia Interchange Break-In-Access Study -, , I , 'r I '1.0119" .~'=-"-. I. ,_:,~;:~:i~::_;~;! i~ I . \ , \ \ . \ , \ . \ . \ . I I I I f--------- I I .~1 . . - -. -.~:: -= I ----_!- Legend .. NcIIng Removel - F.- .. MecIIlIn -.- IUght-of-W.y - 8Iope .0(1 " ,M 'f -..,., ~~-~--~- - IIUOB, WI1IS . RA'lIJ" .... ____ . ........... . MCHnCTI Figure 4 I I I I I I I I I I I I I I I I I I I MAGNOLIA ROAD/I-135 Break-in-Access Study Construction Management of Traffic The management of traffic during construction will vary in complexity and severity depending upon the drainage and bridge options selected. These decisions will impact traffic movement on Magnolia Road over 1-135, traffic movement on 1-135 and access to adjacent property. The decision whether to replace the Magnolia Road Bridge over 1-135 will impact traffic use of Magnolia Road and re-routing of traffic on 1-135. In the case where the existing bridge would remain inplace, traffic could be maintained on 1-135 continuously. Magnolia Road over 1-135 would need to be closed for a short time. H the bridge is replaced, 1-135 would need to be temporarily closed for the demolition of the old bridge and Magnolia Road would need to be closed across 1-135. Access to individual properties from Magnolia Road could be easily maintained throughout the duration of the project. Maintenance of traffic during construction will also be impacted by the drainage scenario alternative which is selected. On alternatives where the drainage scenario includes upgrading drainage structures under 1-135, each direction of 1-135 will need to be shut down in turn and traffic routed to the other side during box construction. Environmental Concems Preliminary review by the consultant and by the Kansas Deparmtent of Transportation indicates that the construction of a diamond interchange at this location should not create significant environmental impacts. Cost Estimates A crucial factor in selection of a preferred alternative is the cost of construction and right-of-way acquisition. Although development of these costs without the benefit of project engineering and right-of-way appraisal cannot be expected to be precise, reasonable estimates can be prepared based an engineering experience and judgement. Unit costs were compared with actual bid tabulations of the recent Schi1Iing Road Interchange Project. A summary of costs has been provided for all six alternatives in Table 5. Detailed cost tabulations are included in the appendix. The results of the estimates is a total project cost, including construction, right-of-way, engineering and contingency, ranging from $4.4 million to $8.2 mi1lion. Bucher, WUUs & RlltlU1- 31 I I I I I I I I I I I I I I I I I I I MAGNOLIA ROAD/I-135 Break-in-Access Study I Table 5 I PROJECI' ALTERNATIVE cosr SUMMARY Alternative 1 2 3 4 5 6 Bridge Scenario (1) (1) (1) (3) (3) (3) Drainage Scenario (1) (2) (3) (1) (2) (3) 1993 Construction Cost Bridge $113,000 $113,000 $113,000 $929,000 $929,000 $929,000 Roadway $2,393,000 $2,393,000 $2,393,000 $2,626,000 $2,626,000 $2,626,000 Drainage $203,000 $564,000 $1,672,000 $203,000 $564,000 $1,672,370 Subtotal $2,709,000 $3,070,000 $4,178,000 $3,158,000 $4,119,000 $5,227,000 10% Contingency $271,000 S307,000 $418,000 $376,000 $412,000 $523,000 Total $2,980,000 $3,377,000 $4,596,000 $4,130,000 $4,531,000 $5,750,000 1996 Construction Cost $3,469,000 $3,931,000 $5,3S0,ooo $4,812,000 $5,274,000 $6,693,000 Construction Engineering 5347,000 $393,000 $535,000 S481,000 $527,000 $669,000 00%) R.O.W. Cost $357,000 $357,000 $390,000 $357,000 $357,000 $390,000 Utility Cost $0 $0 $0 $0 $0 $0 Preliminary Eng. (7%) $209,000 5237,000 $322,000 $289,000 $317,000 S402,000 ESTIMATED TOTAL PROJECI' COST $4,382,000 $4,918,000 $6,597,000 $5,939,000 $6,475,000 $8,154,000 Recommendation The recommended improvement is Alternative 4 as listed in Table 5. The alternative includes Drainage Scenario 1 which involves constructing 9-foot by 7-foot RCBs under each ramp. These structures would have the same hydraulic capacity as the structures under 1-135. The recommended alternative would also replace the existing bridge over 1-135 with a new three-lane bridge. The new bridge would provide an extended service period well beyond that provided by rehabilitating the existing bridge. The new bridge would also meet current design standards. The estimated cost of the recommended alternative is approximately $5.94 million, which includes engineering, inspection and contingency. Bucher, WfWs & RatlUf- 82 I I I I I I I I I I I II I I I I I I I I I MAGNOLIA ROAD/I-135 Break-in-Access Study VI. IMPLEMENTATION Overview The Intermodal Surface Transportation Efficiency Act (ISTEA) of 1991 changed the way federal funds are aIIocated to transportation projects. I5TEA provides unprecedented flexibility in funding. Federal funds can now be aIIocated more easily to the various modes of transportation including highways, transit, pedestrian facilities, bicycle facilities and other project types. The old classification systems such as federal-aid primary and federal-aid urban have been replaced with the National Highway System and a 10caIIy defined arterial street system. Federal funds were made available specifica1Iy for the Magnolia and 1-135 Interchange as part of a list of federal demonstration projects. These funds are not part of the Surface Transportation Program funding. Rather, a set amount of funds were made available specifica1Iy for the Magnolia Road Interchange. These funds are not available for any other project. A maximum funding amount of $2,536,000 is available for the 80 percent federal funding portion. The City of Salina sha1I provide 20 percent local match equaling an amount of $634,000. This amount of funding from both sources equals $3,170,000. Project costs above $3,170,000 will be funded solely by the City of Salina. Project Costs A series of six project costs were prepared which included costs with and without bridge replacement and with three levels of drainage improvements. The recommended improvement includes replacement of the existing bridge with a three-lane bridge. It also includes construction of box culverts under the ramps to accommodate future drainage improvements. The cost estimate has been calculated following the procedures used by the KOOT. Year 1993 construction costs were calculated by adding estimated bridge, roadway and drainage costs, plus a ten percent contingency. The 1996 estimated construction cost factors the costs to reflect three years of inflation using the current KDOT annual construction cost inflation factor of 5.2 percent. Construction engineering inspection (10 percent), right-of-way cost, utility cost relocation and preliminary engineering-d.esign (7 percent) were added to obtain the estimated total project cost. The estimated cost of the recommended alternative for the construction year of 1996 is $5,939,000. Bucher. WfUfs & RatlUT. 33 I I I I I I I I I I I I I I I I I I I MAGNOLIA ROAD/I-135 Break-in-Access Study Project Funding The project funding would be comprised of fedem1 demonstration funds and local funding sources. The local funds Il'\'ly be raised through a public - private partnership involving a special assessment district of affected property owners, the Salina Airport Authority and the City of Salina. The project funding is listed in Table 6. . Table 6 PROJECI' FUNDING (1996 $) Project Cost $5,939,000 Federal Share $2,536,000 Local Share $3,403,000 Construction Schedule The project will require approval by the City of Salina, the KDOT and the Federal Highway Administration. These approvals could be obtained within a six-month period. Plans and specifications would be produced in 12 months enabling a start of construction by January, 1996. The project would be expected to be completed by September, 1997. Bw:hsr. WIllis & RatlUT. 34 I I I I I I I I I I I I I I I I I I I I MAGNOLIA ROAD/I-135 Break-in-Access Study vn. CONCLUSION The putpose of this study has been to determine the feasibility of constructing an interchange with Interstate 135 at Magnolia Road. This study has examined the project in terms of economic development potential, current and future traffic volumes, and benefits associated with improved access to the Interstate Highway System. This report has been prepared following the guidelines for justification of additional access points to the Interstate Highway System. This study has concluded that an interchange at Magnolia Road and 1-135 would be feasible. lncJuded in the report is a description of the configuration of the recommended interchange, its cost and available funding sources; The estimated total cost of the interchange is $5.94 million (1996 $) of which $2.54 million will be funded by a federal highway demonstration grant. Bucher, Willis & RatlUT' 35 I I I I I I I I I I I I I I I I I I I MAGNOLIA ROAD/I-135 Break-in-Access Study APPENDIX Detailed Cost Estimates Bucher. Willis & Rat1UT. 36 I I I I I I I I I I I I I I I I I I I I MAGNOLIA ROAD/I-135 Break-in-Access Study BRIDGE SCENARIO 1 EXISTING STRUCTURE REHABILITATION ALTERNATE PRELIMINARY COST ESTIMATE Item Quantity Unit Unit Cost Extension Bridge Rail 470 Lin.Ft. $100.00 $47,000 Machine Preparation (3/4") 625 Sq. Yds. $20.00 $12,500 Area Prepared for Patching 95 Sq. Yds. $115.00 $10,925 Area Prepared for Patching 65 Sq. Yds. $275.00 $17,875 (Full Depth) Bridge Deck Wearing Surface 625 Sq. Yds. $40.00 $25,000 01/2") TOTAL (rounded) $113,000 Bucher, WIllis & RatlUT. 37 I I I I I I I I I I I II I I I I I I I I MAGNOLIA ROAD/I-135 Break-in-Access Study BRIDGE SCENARIO 2 REHABILITATION AND WIDENING ALTERNATE PRELIMINARY COST ESTIMATE Item Quantity Unit Unit Cost Extension Class III Excavation 200 C.Y. $30.00 $6,000 Class AAA Concrete (AE) 135 C.Y. $220.00 $29,700 Class AAA Concrete (AE)(SA) 195 C.Y. $250.00 $48,750 Reinforcing Steel (GR.60) 5,000 Lbs. $0.45 $2,250 Reinforcing Steel (GR.6D-Epoxy) 78,000 Lbs. $0.50 $39,000 Structural Steel (AASHTO M-222) 148,000 Lbs. $0.80 $118,400 Structural Steel (ASTM A588) 37,000 Lbs. $0.80 $29,600 Headed Stud Anchors 1,800 Each $2.00 $3,600 Steel Piles 4,400 L.F. $20.00 $88,000 Bearing Devices 30 Each $450.00 $13,500 Longitudinal Expansion Devices 470 L.F. $125.00 $58,750 Concrete Removal 68 C.Y. $200.00 $13,600 Machine Preparation (3/4") 535 S.Y. $20.00 $10,700 Area Prepared for Patching 80 S.Y. $115.00 $9,200 Area Prepared for Patching 55 S.Y. $275.00 $15,125 (Full Depth) Silica Fume Wearing Surface 1,248 S.Y. $40.00 $49,920 TOTAL (rounded) $536,000 Bucher, WilUs & RldlUT. 88 I I I I . I I I. I il ! . I I . I I . I I MAGNOLIA ROAD/I-135 Break-in-Access Study BRIDGE SCENARIO 3 NEW STRUcruRE PREUMINARY COST ESTIMATE Item Quantity Unit Unit Cost Extension Class III Excavation 170 c.Y. $30.00 $5,100 Class AAA Concrete (AE) 425 C.Y. $220.00 $93,500 Class AAA Concrete (AE)(SA) 380 c.Y. $250.00 $95,000 Silica Fume Wearing Surface 1470 S.Y. $40.00 $58,800 Reinforcing Steel 166,000 Lbs. $0.50 $83,000 (Gr. 6D-Epoxy) Structural Steel 115,000 Lbs. $0.80 $92,000 (AASHTO M-222) Structural Steel (ASTM A588) 345,000 Lbs. $0.80 $276,000 Headed Stud Anchors 3,300 Each $2.00 $6,600 Steel Piles 5,000 L.F. $20.00 $100,000 Expansion Devices 106 L.F. $200.00 $21,200 Bearing Devices 18 Each $450.00 $8,100 Removal of Existing Structure 1 L.S. $90,000.00 $ 90,000 TOTAL (rounded) $929,000 Buc"-'r. WfUis & RatlU1' . 39 II I 'I I I I I I II I I I I I I I I I I I I MAGNOLIA ROAD/I-135 Break-in-Access Study DRAINAGE SCENARIO 1 SINGLE 9' X 7' RCB Item Quantity Unit Unit Cost Extension Construct 9' x 7' x 240' RCB under East Ramp L. S. - - $104,200 Construct 9' x 7' x225' RCB under West Ramp L. S. - - $98,700 TOTAL (rounded) $203,000 Bucher, WlUis & RatlUT. 40 Ii. I I I I I I I I I I I I I I I I II I I MAGNOLIA ROAD/I-135 Break-in-Access Study DRAINAGE SCENARIO 2 3-10' X 7' RCBS UNDER RAMPS Item Quantity Unit Unit Cost Extension Construct 3-10' x 7' x 240' RCBs under East Ramp Lump Sum - - $289,000 Construct 3-10' x 7' X 225' RCBs Lump Sum - -- $267,000 Excavate 40' Flat Bottom Channel between 1-135 and East Ramp 1,200 c.Y. $3.00 $3,600 Execavate 40' Flat Bottom Channel between West Ramp and 1-135 1,400 c.Y. $3.00 $4,200 TOTAL <rounded) $564,000 Bucher, WUUS & RatlCff - 41 I I I I I I I I I I I I I I I I I I I MAGNOLIA ROAD/I-135 Break-in-Access Study DRAINAGE SCENARIO 3 3-10' X 7' RCBS UNDER RAMPS 2-10' X 7' RCBS AND 1-9' X 7' RCB UNDER 1-135 DITCH IMPROVEMENTS Item Quantity Unit Unit Cost Extension Magnolia Road Ditch Construction 3-10' x 7' x 240' RCBs under Interchange East Ramp L. S. - $289,000 Add 2=10' x 7' x 200' RCBs to the Existing 9' x 7' RCB under 1-135 L.S. $229,500 Construct 3-10' x 7' x 225' RCBs under Interchange West Ramp L. S. - $267,000 Add 2-10' x 7' x 40' RCBs to the Existing 9' x 7' RCB under Farm Home Entrance L.S. - $55,400 Add 2-10' x 7' x 40' RCBs to the Existing 9' x 7' RCB under Field Entrance L. S. - $55,400 Excavate 40' Flat Bottom Channel between East Ramp and Entrance to Shopping Center 9,750 c.Y. $3.00 $29,250 Excavate 40' Flat Bottom Channel between 1-135 and East Ramp 1,200 c.Y. $3.00 $3,600 Excavate 40' Flat Bottom Channel between West Ramp and 1-135 . 1,400 c.Y. $3.00 $4,200 Excavate 40' Flat Bottom Channel between Field Entrance and West Ramp 15,500 c.Y. $3.00 $46,500 Excavate 40' Flat Bottom Channel between Dry Creek Channel to Field Entrance 13,200 c.Y. $3.00 $39,600 Seeding, Mulching and Fertilizing 18 Acres 1,750 $31,500 Sub-Total Consbuctlon Cost $1,050,950 Bucher, WlWs & RatlUr. 42 I I I I I I I I I I I I I I I I I I I MAGNOLIA ROAD/I-135 Break-in-Access Study DRAINAGE SCENARIO 3 3-10' X 7' RCBS UNDER RAMPS 2-10' X 7' RCBS AND 1-9' X 7' RCB UNDER 1-135 DITCH IMPROVEMENTS Item Quantity Unit Unit Cost Extension Dry Creek Channel Improvements (These quantities are taken directly from the 1986 Engineering Report - the quantities have not been recalculated) Clearing, Stripping and Grubbing 11 Acres $2,000 $22,000 Excavation of 40' Flat Bottom Ditch 161,700 c.Y. $2.50 $404,250 Seeding and Mulching 30 Acres $1,750 $52,500 Sub-Total Construction Cost $478,750 Cross Over on 1-135 Construct 2 Cross Overs 1. S. $112,550 Pavement Reconstruction 1. S. $30,120 Sub-Total Construction Cost $142,670 TOTAL CONSTRUCTION COST (rounded) $1,672,(100 Right-of-Way and Easements Channel - Public 51 Acres 0 00 Channel - Private 17 Acres $1,500 $25,500 Additional Right-of-Way 5 Acres $1,500 $7,500 TOTAL RIGHT-OF-WAY COST $33,000.00 Bucher, Willis & Ratl(ff. 43 I .. I . I . . . . . . . . I . . . . . MAGNOLIA ROAD/I-135 Break-in-Access Study ROADWAY COSTS WITH EXISTING BRIDGE Item Quantity Unit Unit Cost Extension Mobilization 1. S. - - $120,000 Field Office 1. S. - - $5,000 , Contractor Construction Staking L.S. - - $30,000 Clearing and Grubbing 1. S. - - $5,000 Unclassified Excavation 305,240 C. Y. $2.00 $610,480 Compaction, Type AA, MR-D .16,000 C. Y. $0.60 $9,600 Compaction, Type B, MR-9O 219,300 C.Y. $0.60 $131,580 8" Concrete Pavement 26,650 S. Y. $25.00 $666,250 4" Granular Subbase 30,450 S. Y. $5.00 $152,250 Inlets 10 Each $2,000.00 $20,000 Storm Sewer 600 L. F. $30.00 $18,000 Fence 5600 L.F. $6.00 $33,600 Guard Rail 2100 L.F. $20.00 $42,000 Concrete Safety Barrier 890 1. F. $30.00 $26,700 Curb & Gutter 1350 1. F. $9.00 $12,150 Median Surface - - - - Retaining Wall 5080 S. F. $30.00 $152,400 Fertilizer Seeding & Mulching 35 Acres $360.00 $12,600 Ughting L. S. - - $80,000 Traffic Control L.S. - - $20,000 Marking 1. S. - - $15,400 Permanent Signing 1. S. - - $90,000 Signalization 1. S. - - $140,000 TOTAL (rounded) $2,393,000 Bucher, WflIfs & RatlUT. 44 I I I I I I I I I I I I I I I I I I I MAGNOLIA ROAD/I-135 Break-in-Access Study ROADWAY COSTS WITH NEW BRIDGE Item Quantity Unit Unit Cost Extension Mobilization L. S. - - $200,000 Field Office L. S. - - $5,000 Contractor Construction Staking L. S. - - $35,000 Gearing and Grubbing L.S. - - $5,000 Unclassified Excavation 325,360 C. Y. $2.00 $650,720 Compaction, Type AA, MR-D 17,300 C. Y. $0.60 $10,380 Compaction, Type B, MR-90 233,500 C. Y. $0.60 $140,100 8" Concrete Pavement 27,410 S. Y. $25.00 $685,250 4" Granular Subbase 33,700 S. Y. $5.00 $163,500 Inlets 10 Each $2,000.00 $20,000 Storm Sewer 600 L. F. $30.00 $18,000 Fence 5600 L. F. $6.00 $33,600 Guard Rail 2100 L. F. $20.00 $42,000 Concrete Safety Barrier 890 L. F. $30.00 $26,700 Curb & Gutter 1350 L.F. $9.00 $28,350 Median Surface 1490 S. Y. $25.00 $37,250 Retaining Wall 5080 S. F. $30.00 $152,400 Fertilizer Seeding & Mulching 35 Acre $360.00 $12,600 Ughting L.S. - - $80,000 Traffic Control L.S. - - $30,000 Marking L. S. - - $20,000 Permanent Signing L.S. - - $90,000 Signalization . L. S. - - $140,000 TOTAL (rounded) $2,626,000 Bucher, WfUis & RatllU. 45 I I I I I I I I I I I I I. I I I I I I MAGNOLIA ROAD/I-13S Break-in-Access Study RIGHT-OF-WAY COSTS FOR INTERCHANGE IMPROVEMENTS Location Use Area Unit Cost Extension Southeast Quadrant Detention Basin 125,000 SF $0.25 $31,250 Northwest Quadrant Farm land 128,000 SF $0.05 $6,400 Southwest Quadrant Farm land 220,000 SF $0.05 $11 ,000 Northeast Quadrant Trailer Park 167,000 SF $0.60 $100,200 Northeast Quadrant Trailer Park 16 Trailers $13,000 $208,000 Relocated TOTAL (rounded) $357,000 Bucher, WfUis & RatlUf- 46