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D2 Roadway Discussion Sound Transit Board September 22, 2011.

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Presentation on theme: "D2 Roadway Discussion Sound Transit Board September 22, 2011."— Presentation transcript:

1 D2 Roadway Discussion Sound Transit Board September 22, 2011

2 Today’s Presentation Up-date on the D2 Analysis Discussion next steps 2

3 D2 Transitway Operations 3 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

4 Future Light Rail Network 4 Kent / Des Moines Lynnwood Overlake Northgate 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 D2 Transitway Area 8-min. Headways/ 4-car trains 4-min. Headways

5 Status of Analysis 5 Operations and Administration Committee was briefed on the D2 Roadway operations at the July 21 st 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

6 D2 Busway Joint Use ROW 6 D2 covers 1.4 miles Several tight curves and grades EB and WB lanes separated by barrier

7 Rail Operations on the D2 (Under Joint Operations) 7 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

8 Bus Only Lane on the D2 8 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

9 Surface Street Options 9 D2 would be rail only Buses would use either I-90 mainline to 4 th 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

10 Bus Integration Option Route Current Headway (minutes)AM Peak Origin 21210Eastgate P&R 21420Issaquah 21530North Bend 21630Sammamish 21812Issaquah Highlands Bus travel times are longer to the south end of downtown due to transfer Bus hours savings could be redeployed

11 Conclusions 11 Joint Operations:Delays both buses and trains Bus Only Lane:Improves travel times for bus and trains but additional design is needed Surface Streets:Buses delayed by congestion, especially in the PM and during events Bus Integration:Increases transfers for bus passenger but significant operating hours saved

12 Next Steps 12 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

13 Summary of Options Considered 13

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