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D2 Roadway Discussion Sound Transit Board September 22, 2011. Today’s Presentation. Up-date on the D2 Analysis Discussion next steps. D2 Transitway Operations. EIS evaluates joint bus-rail operations and rail only operation Both options are feasible
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D2 Roadway Discussion Sound Transit Board September 22, 2011
Today’s Presentation • Up-date on the D2 Analysis • Discussion next steps
D2 Transitway Operations • EIS evaluates joint bus-rail operations and rail only operation • Both options are feasible • During the East Link construction the D2 will be closed to all traffic • Experience with Downtown Seattle Transit Tunnel (DSTT) indicates joint operations impacts transit reliability 3
Future Light Rail Network Lynnwood • Two operating lines in the future • The peak load point for the system is in the DSTT • Assumes 8 min. headways and 4-car trains • Critical that NB trains from the south and east arrive at the merge point on schedule • Potential to operate 6-min. headways with 3-car trains Northgate 4-min. Headways Overlake D2 Transitway Area 8-min. Headways/ 4-car trains Kent / Des Moines
Status of Analysis • Operations and Administration Committee was briefed on the D2 Roadway operations at the July 21st meeting • Since July ST has been working closely with Metro, WSDOT, and the City of Seattle to refine options which include: • Modifications to joint operations • Adding a bus only lane on the D2 • Surface options if buses do not use the D2 • Possible bus/rail integration options at S. Bellevue Park & Ride and Mercer Island
D2 Busway Joint Use ROW • D2 covers 1.4 miles • Several tight curves and grades • EB and WB lanes separated by barrier
Rail Operations on the D2(Under Joint Operations) • With joint operations trains will not be able to use Automatic Train Protection (ATP) mode which potentially affects safety and reliability • Instead trains will operate in line of sight mode: • “Operate at a speed that would allow the operator to identify, react and stop the train within ½ of the distance of the obstruction ahead.” • Train speeds under joint operations are estimated to be 1 minute slower WB and 1.5 minutes slower EB
Bus Only Lane on the D2 • Light rail tracks would be constructed to one side • An 11ft wide bus lane would be added to the D2 • Bus lane evaluated as reversible or outbound only • Bus travel times are faster than with joint use • Light rail vehicle would be able to run in ATP mode • Additional engineering is required, as is approval from WSDOT and FHWA
Surface Street Options • D2 would be rail only • Buses would use either I-90 mainline to 4th Ave or Rainier Ave and Dearborn St. to and from downtown • Results in longer bus travel times, especially in the PM peak period • Affects bus reliability
Bus Integration Option • Bus travel times are longer to the south end of downtown due to transfer • Bus hours savings could be redeployed
Next Steps • With Board concurrence, ST will recommend to FTA that the ROD specify rail only on the D2 Roadway • ST and King County will enter into an agreement and develop a work plan to evaluate the busway option and other options including bus/rail integration • If the busway option proves to be unfeasible, ST and KCM will jointly reconsider other alternatives