Maine Turnpike Needs Assessment Safety and Capacity Study Prepared for: Maine Turnpike Authority Prepared by: May 2016 ii | Page TABLE OF CONTENTS EXECUTIVE SUMMARY .......................................................................................................................................... 1 1.1 Purpose and Scope .................................................................................................................................. 1 1.2 Turnpike Assets ....................................................................................................................................... 1 1.3 Current Traffic Observations ............................................................................................................... 2 1.4 Safety Needs Identified ........................................................................................................................... 3 1.5 Capacity Needs Identified ...................................................................................................................... 4 1.6 Planning Study Needs Identified ........................................................................................................... 5 2 INTRODUCTION ........................................................................................................................................... 7 3 EXISTING CONDITIONS........................................................................................................................... 10 3.1 Data Collection ...................................................................................................................................... 11 3.2 Traffic Characteristics ........................................................................................................................... 11 3.3 Average Annual Daily Traffic............................................................................................................... 12 3.3.1 Seasonal Variation ......................................................................................................................... 16 3.4 Existing Level of Service Analysis ....................................................................................................... 17 3.4.1 LOS Analysis Assumptions ......................................................................................................... 17 3.4.2 Interchange Merge Sections ....................................................................................................... 18 3.4.3 Interchange Diverge Sections .................................................................................................... 23 3.4.4 Mainline Travel Sections ............................................................................................................. 28 3.4.5 Summary – Existing Level of Service Analysis ........................................................................ 29 4 FUTURE CONDITIONS .............................................................................................................................. 31 4.1 Growth Rate Calculations ................................................................................................................... 31 4.2 Interchange Merge Sections ................................................................................................................ 32 4.3 Interchange Diverge Sections ............................................................................................................. 35 4.4 Mainline Sections .................................................................................................................................... 39 4.5 Summary of Future Conditions .......................................................................................................... 40 5 VISSIM Traffic Analysis for the Portland Area......................................................................................... 44 5.1 VISSIM Analysis Methodology ............................................................................................................. 44 5.2 2014 Traffic Analysis ............................................................................................................................. 47 5.3 2024 Traffic Analysis ............................................................................................................................. 49 5.4 2034 Traffic Analysis ............................................................................................................................. 51 6 VISSIM Traffic Analysis for the Biddeford/Saco Area ............................................................................ 54 6.1 Methodology ........................................................................................................................................... 54 6.2 2014 Traffic Analysis ............................................................................................................................. 57 6.3 2024 Traffic Analysis ............................................................................................................................. 58 6.4 2034 Traffic Analysis ............................................................................................................................. 59 7 SAFETY CONDITIONS ............................................................................................................................... 62 7.1 Crash Rate Comparison ....................................................................................................................... 62 7.2 Current Safety Practices ...................................................................................................................... 63 7.3 Safety Improvement Projects .............................................................................................................. 65 7.4 Other Studies .......................................................................................................................................... 67 i | Page 7.5 High Crash Locations ............................................................................................................................ 68 7.5.1 High Crash Locations 2009-2011 Update ............................................................................... 68 7.5.2 Current High Crash Locations of the Maine Turnpike ....................................................... 73 8 COST ANALYSIS ........................................................................................................................................... 78 9 RECOMMENDATIONS/SUMMARY OF FINDINGS ............................................................................ 80 Appendix A Level of Service Description ....................................................................................................... 82 Appendix B Non-Typical Diverge Calculations ............................................................................................ 85 Appendix C Forecasted Volumes & LOS ....................................................................................................... 86 Appendix D High Crash Location Diagrams.................................................................................................. 94 Appendix E Peak Hour Growth Rate Forecasts ........................................................................................ 105 E-1. Background ........................................................................................................................................... 105 E-2. Introduction ......................................................................................................................................... 105 E-3. Historic Peak Hour Traffic Growth ............................................................................................... 106 E-4. Other Traffic Forecasts ..................................................................................................................... 107 E-5. Conclusions .......................................................................................................................................... 107 Appendix F. Additional VISSIM Traffic Analysis for the Exit 36 Southbound Off-Ramp ................... 108 F.1 Methodology .................................................................................................................................................... 108 F.2 Site Visit............................................................................................................................................................ 108 F.3 2014 and 2015 Traffic Analysis ................................................................................................................... 109 F.4 2034 No-Build Traffic Analysis ...................................................................................................................... 110 F.5 2034 Traffic Analysis of Alternatives ............................................................................................................ 111 F.6 Conclusions ...................................................................................................................................................... 113 LIST OF TABLES Table ES-1 – 2012-2014 HCLs on the Maine Turnpike .................................................................................... 3 Table ES-2 – Annual Peak Hour Growth Projections ......................................................................................