Concept Report STATE STREET-VMP-36TH STREET INTERSECTION CONCEPT DESIGN ACHD PROJECT NO. 611026 Ada County Highway District SIX MILE ENGINEERING, PA APRIL 8, 2013 TH STATE STREET-VMP-36 STREET INTERSECTION CONCEPT REPORT CONCEPT DESIGN ACHD PROJECT NO. 611026 Report Summary The Ada County Highway District (ACHD) retained Six Mile Engineering, PA, to evaluate the existing conditions at the State Street-VMP-36th Street intersection and propose potential improvements to enhance the functionality for all users – pedestrians, bicyclists, transit riders and motorists. The proposed improvements incorporate the future widening of State Street to include a transit and high-occupancy vehicle lane, designated by the Transit and Traffic Operations Plan (TTOP) recently adopted by ACHD and partner jurisdictions. The Project Team considered almost two dozen proposed innovative intersection alternatives and evaluated their suitability and compatibility with the needs of the different users. Through multiple evaluation stages with increasing levels of refinement, a preferred intersection alternative was identified. Stakeholder and public input were a key component throughout the evaluation process. Their input was utilized to identify key issues, refine intersection alternatives and help select a preferred alternative. The preferred intersection alternative identified by the Project Team, a Partial Median U-turn intersection, most effectively balanced the needs of all users while also minimizing construction cost and property impacts. The Partial Median U-Turn intersection re-routes left turns on State Street through the intersection and downstream to signalized median U-turn locations. This innovative treatment of left- turns results in more efficient intersection operations, improving mobility on State Street and reducing delays for motorists, pedestrians and bicyclists traveling through the intersection. On March 27, 2013, the ACHD Commission adopted the Partial Median U-Turn intersection as the preferred alternative for improvements at the State Street-VMP-36th Street intersection. SIX MILE ENGINEERING, PA APRIL 8, 2013 PAGE I TH STATE STREET-VMP-36 STREET INTERSECTION CONCEPT REPORT CONCEPT DESIGN ACHD PROJECT NO. 611026 Table of Contents Report Summary ......................................................................................................................................... I Project Description .................................................................................................................................... 1 Preferred Alternative – Partial Median U-Turn ........................................................................................ 3 Project Team and Stakeholder Team ...................................................................................................... 4 Roadway Cross Sections ......................................................................................................................... 4 Intersection Turn Lanes ........................................................................................................................... 5 Pedestrian and Bicycle Facilities ............................................................................................................. 5 Transit Facilities ....................................................................................................................................... 6 Construction Cost and Right-of-Way Impacts .......................................................................................... 7 How Was the Preferred Alternative Developed?..................................................................................... 8 Project Approach ..................................................................................................................................... 8 Key Design Criteria .................................................................................................................................. 9 Previous Plans and Studies ................................................................................................................... 10 How was the Public Involved?................................................................................................................ 11 Interactive Website Survey .................................................................................................................... 11 Stakeholder Meetings ............................................................................................................................ 12 Public Involvement Meeting ................................................................................................................... 12 What are the Intersection Challenges, Constraints and Design Criteria?.......................................... 14 Vehicles ................................................................................................................................................. 14 Pedestrians ............................................................................................................................................ 15 Bicyclists ................................................................................................................................................ 17 Safety ..................................................................................................................................................... 18 Transit .................................................................................................................................................... 19 Land Use ............................................................................................................................................... 20 Drainage ................................................................................................................................................ 20 Utilities ................................................................................................................................................... 20 Environmental ........................................................................................................................................ 21 Right-of-Way .......................................................................................................................................... 21 Taft Elementary School ......................................................................................................................... 21 Veterans Memorial Park ........................................................................................................................ 22 Albertsons .............................................................................................................................................. 22 Access ................................................................................................................................................... 22 How Were the Intersection Alternatives Analyzed? ............................................................................. 23 22 Initial Alternatives .............................................................................................................................. 23 Alternative Development .................................................................................................................... 23 Screening-Level Evaluation ............................................................................................................... 23 Ten Preliminary Alternatives .................................................................................................................. 25 Five Final Alternatives ........................................................................................................................... 26 Alternative Evaluation ........................................................................................................................ 26 SIX MILE ENGINEERING, PA APRIL 8, 2013 PAGE II TH STATE STREET-VMP-36 STREET INTERSECTION CONCEPT REPORT CONCEPT DESIGN ACHD PROJECT NO. 611026 Preferred Alternative Evaluation and Ranking ................................................................................... 27 Appendix A – Final Alternative Concept Design Layouts ..................................................................... A Appendix B – 22 Initial Alternatives ........................................................................................................ B Appendix C – Screening Matrix for Determining Preliminary Intersection Alternatives.................... C Appendix D – Screening Matrix for Determining Final Intersection Alternatives ............................... D Appendix E – Rating and Ranking of Final Intersection Alternatives.................................................. E Appendix F – Traffic Analysis Summary ................................................................................................. F Appendix G – Triple Northbound Left-Turn Analysis Memo ................................................................ G Appendix H – Summary of Interactive Website Survey Comments ..................................................... H Appendix I – Public Comment Summary .................................................................................................. I Appendix J – Land Use and Transit Analysis and Evaluation............................................................... J Appendix