Washington

City: 
Seattle
Facilities: 
US 2
Facility Type: 
Freeway shoulder
Description: 
Eastbound direction of trestle, right shoulder; 1.55 miles
Objectives: 
To improve travel times, reduce impacts of bottlenecks, and relieve congestion at a critical interchange.
Date Implemented: 
2009
Date Terminated: 
N/A
Other Information: 
Restriping allows three different movements to remain in their own lanes when shoulder use is allowed; minimizes weaving; each destination (SR 204, 20th St SE, and US2 EB) reached from separate lane when shoulder use allowed.
Operational Information
Allowed Vehicles: 
All vehicles
Operating Partners: 
WSDOT
Operational Hours: 
M-F, 3 PM - 7 PM
Conditions: 
Application is permanent for the near future; should be able to accommodate traffic growth over the next few years.
Maximum Speed: 
60 mph
Oversize Vehicles: 
N/A
Geometric Features
Cross Section Details: 
2 ft left shoulder, 2 11 ft lanes, 14 ft right shoulder
Treatment at Interchanges: 
Crosses one exit ramp to Homeacres Road (low volumes exiting); required a redesign of the gore and recovery area; restriping places traffic closer to gore and barrier
Handling of Inlets: 
N/A
Handling of Rumble Strips: 
N/A
Guardrail and Fixed Objects: 
One barrier had to be minimized and allow for wider shoulder.
Pull Off Areas: 
N/A
Pavement: 
N/A
Traffic Control Devices
Pavement Markings: 
Typical skip stripe and solid stripe
Overhead Signs and Signals: 
Overhead sign to the Homeacre Road exit; no LCS
Ground Mounted Signs: 
shoulder mounted or on barrier as 1200' intervals; manual flip signs: SHOULDER OPEN TO TRAFFIC; SHOULDER CLOSED; additional glare screening installed as barrier to discourage pedestrian and bicycle activity on trestle.
ITS: 
None on this segment; DMS on I-5 can support operations
Performance Measures
Monitoring Responsibilities: 
WSDOT
Operational Effectiveness: 
Primary performance measure is travel time; delay reduced from 8-10 minutes to 1-2 minutes on facility; travel times much more reliable; have increased throughput on the ramps - ramp operates at or near capacity during most of peak period; peak 15 minute flow rate 4320/hr; 2100 vehicles during 3 PM - 7 PM period;
Safety Evaluation: 
Too early to confidently assess safety improvements; anecdotal evidence is that collisions at the conflict point where the three roads merge on the trestle have been reduced; difficult to measure since deployment coincided with ramp metering on I-5 which feeds US 2.
Other Impacts: 
Average speed on SR 2 after implemementation of shoulder use and I-5 ramp metering increased from 10 mph to 37 mph - close to maximum of 42 mph because of ramp curvature;
Costs: 
$70,000
Enforcement
Responsibility: 
Washington State Patrol
Fines: 
unknown
Approach: 
visual inspection
Maintenance: 
WSDOT Incident Response team out of maintenance; Washington State Patrol
Incident Reponse
Responsibilties: 
All incidents occurring on shoulder treated as lane blocking and begin notification process.
Average Response Time: 
Unknown
Strategies: 
Mainline I-5 DMS used to notify drivers of shoulder-lane incidents. If shoulder closure is due to inclement removal or log removal operation, signs are flipped and flashing beacons are attached to signs and I-DMS are used.
Operational Experience: 
Provides significant and reliable travel time benefits. SOP are to have maintenance drive shoulder 1 hour prior to opening to ensure it is clear; TMC staff sweep trestle with CCTV 30 minutes prior to opening;
Institutional Issues
Liability: 
Biggest concern was whether driving public would understand the signing and pavement markings. Has not appeared to be a problem.
Public Outreach: 
Typical outreach to the public using the media; there was great support from the City of Everett. Deployment has greatly improved the afternoon commute out of Everett.
Legislation: 
None
Difficulty: 
About 60 violators a day leading up to 3 PM opening; increasing after 2 PM; about 35 a day after 7 PM