PROTECTING THE SILVER LINE FROM CONGESTION IN DUDLEY SQUARE - PowerPoint PPT Presentation

PROTECTING THE SILVER LINE FROM CONGESTION IN DUDLEY SQUARE GUILHERME TOMIYOSHI NAKAO M.S. CIVIL ENG. - TRANSPORTATION ENG. ADVISOR: PETER G. FURTH NORTHEASTERN UNIVERSITY 05/26/2016

AREA OF STUDY Bus lane Dedicated Bus lane Mixed Traffic Mixed Traffic Dudley Station

AVL DATA: SILVER LINE 5, PM PEAK • Avg. Speed: 4.4 mph • Avg delay: 2.5 min • 95th-p delay: 4.4 min Avg. Speed: 4.4 mph (6.45 ft/s) Dudley Station

Queuing region

Queuing around Dudley Station

Single-lane queuing

Washington St and Warren St junction

Washington St @Ruggles St

Main bottlenecks on Washington St • @ Ruggles St • @ Malcolm X Blvd / Dudley St

Wash. St @ Ruggles St • Unsignalized intersection • Informal priority rules force SB Washington St traffic to stop

Wash. St @ Ruggles St: Cut-Through traffic

WASH. ST @ MALCOLM X BLVD / DUDLEY ST • Insufficient capacity for Phase 1 (30 s out of 100) • Many other problems with this signal • Ped pushbutton = inappropriate • Long crossing (88 ft – equivalent of 8 lanes) • Ped phase (26 s) is non-compliant • Unprotected left turn Dudley-Wash: unsafe, often blocks a lane

DATA COLLECTION • Traffic turning counts • Signal timings • Pedestrian Volumes (at crosswalks and between them) • Bus volumes • Double Parking • Bus travel time from AVL • Modelled on PTV VISSIM

AVL Data 04/05/16 04/06/16 04/07/16

Model features and Calibration • Low free-flow speed (19 mph, 13 mph) • Pedestrians on crosswalks and at dummy crosswalks • Double parking • Special priority rules around Ruggles St. • Occasional single lane queuing in front of Dudley Station • Buses leaving the station encroach on two lanes and force their way in

Validation: SL5 Travel time

Proposed changes: Ruggles St • Change to one-way westbound from Washington St to Shawmut Ave • Similar to W. Newton, Concord and Rutland Streets in the South End

Proposed changes: Malcolm X Blvd / Dudley St • Eliminate northbound left turns (<10 veh/h) • Protected WB left turn • Concurrent pedestrian Phase every cycle

Geometric changes • Crossing distance reduced from 88 to 62 ft • Left turn bay added

PROPOSED SIGNAL TIMING PLAN • Maintains 100 s coordination along Dudley • Increased capacity SB • Ped phases are concurrent, automatic and longer

SL Travel Time: AVL x Base Sim x Proposed changes Silver Line Travel time (s) – AVL x Base x Proposed changes 70% Existing (AVL): Mean 229 s; σ = 86 s 60% Existing (Base Model): Mean 234s; σ = 115 s Proposed: Mean 109 s; σ = 37 s 50% 40% 30% 20% 10% 0% 80 120 160 200 240 280 320 360 400 440 480 520+ AVL data Base model Proposed changes

Contact info Guilherme Tomiyoshi Nakao MS Civil Eng – Transportation Engineering Northeastern University guinakao@gmail.com