New York State Thruway Authority Metropolitan Transportation Authority Metro-North Railroad Alternatives Analysis for Commuter Rail Hudson River Crossing TECHNICAL MEMORANDUM Tappan Zee Bridge/I-287 Corridor Environmental Review Tarrytown Nyack September 26, 2005 TABLE OF CONTENTS Chapter Title Page 1 Introduction/Background ..............................................................1-1 1.1 AA Process......................................................................................................................1-2 1.2 Proposed DEIS Alternatives ............................................................................................1-3 2 Engineering Elements...................................................................2-1 2.1 Operating Requirements ..................................................................................................2-1 2.1.1 NYSTA...............................................................................................................2-1 2.1.2 Metro-North........................................................................................................2-4 2.2 Physical Constraints.........................................................................................................2-5 2.3 Highway-Only Bridge......................................................................................................2-7 2.4 Bridge Option..................................................................................................................2-7 2.4.1 Rockland CRT Shoulder Tunnel (Segments 1 and 2).........................................2-8 2.4.2 River Crossing (Segment 3)..............................................................................2-10 2.4.3 Tappan Zee Station Area (Segment 4)..............................................................2-13 2.4.4 Cross Westchester CRT Shoulder Tunnel (Segment 5)....................................2-15 2.4.5 Hudson Line CRT Connection Tunnel (Segment 6).........................................2-15 2.4.6 Hudson Line Connection (Segment 7)..............................................................2-16 2.4.7 Support Facilities..............................................................................................2-16 2.5 Tunnel Option................................................................................................................2-17 2.5.1 Rockland CRT Shoulder Tunnel (Segments 1 and 2).......................................2-18 2.5.2 River Crossing (Segment 3)..............................................................................2-18 2.5.3 Tarrytown Station Area (Segment 4)................................................................2-25 2.5.4 Cross-Westchester Shoulder Tunnel (Segment 5) ............................................2-26 2.5.5 Hudson Line Connection (Segment 6)..............................................................2-26 2.5.6 Support Facilities..............................................................................................2-27 3 Engineering Criteria.......................................................................3-1 3.1 Fire/Life Safety................................................................................................................3-1 3.1.1 Bridge Option.....................................................................................................3-1 3.1.2 Tunnel Option.....................................................................................................3-2 3.1.3 Comparison of Options.......................................................................................3-3 3.2 Emergency Response.......................................................................................................3-3 3.2.1 Bridge Option.....................................................................................................3-3 3.2.2 Tunnel Option.....................................................................................................3-4 3.2.3 Comparison of Options.......................................................................................3-5 3.3 Redundancy .....................................................................................................................3-5 3.4 Construction Impacts .......................................................................................................3-6 3.4.1 Bridge Option.....................................................................................................3-6 3.4.2 Tunnel Option.....................................................................................................3-7 3.4.3 Comparison of Options.......................................................................................3-8 i TABLE OF CONTENTS Chapter Title Page 3.5 Summary..........................................................................................................................3-9 4 Transportation Criteria..................................................................4-1 4.1 Transit Ridership and Travel Times ................................................................................4-2 4.1.1 Bridge Option.....................................................................................................4-2 4.1.2 Tunnel Option.....................................................................................................4-3 4.1.3 Comparison of Options.......................................................................................4-8 4.2 Transportation System Integration...................................................................................4-8 4.2.1 Bridge Option.....................................................................................................4-8 4.2.2 Tunnel Option.....................................................................................................4-9 4.2.3 Comparison of Options.......................................................................................4-9 4.3 Metro-North Operations................................................................................................4-10 4.3.1 Bridge Option...................................................................................................4-10 4.3.2 Tunnel Option...................................................................................................4-10 4.3.3 Comparison of Options.....................................................................................4-11 4.4 NYS Thruway Operations .............................................................................................4-11 4.4.1 Bridge Option...................................................................................................4-11 4.4.2 Tunnel Option...................................................................................................4-11 4.4.3 Comparison of Options.....................................................................................4-12 4.5 Local Roadway Congestion ...........................................................................................4-12 4.5.1 Bridge Option...................................................................................................4-12 4.5.2 Tunnel Option...................................................................................................4-14 4.5.3 Comparison of Options.....................................................................................4-17 4.6 Rail Freight....................................................................................................................4-17 4.7 Summary........................................................................................................................4-17 5 Environmental Criteria..................................................................5-1 5.1 Displacements, Easements, and Partial Takings..............................................................5-1 5.1.1 Bridge Option.....................................................................................................5-2 5.1.2 Tunnel Option.....................................................................................................5-2 5.1.3 Comparison of Options.......................................................................................5-5 5-2 Land Use..........................................................................................................................5-6 5.2.1 Bridge Option.....................................................................................................5-7 5.2.2 Tunnel Option.....................................................................................................5-7 5.2.3 Comparison of Options.......................................................................................5-8 5.3 Historical/Archaeological Resources...............................................................................5-8 5.3.1 Bridge Option.....................................................................................................5-8 5.3.2 Tunnel Option.....................................................................................................5-9 5.3.3 Comparison of Options.....................................................................................5-10 5.4 Parklands........................................................................................................................5-10 5.4.1 Bridge Option...................................................................................................5-10