Washington

City: 
Seatte
Facilities: 
SR 520
Facility Type: 
Freeway shoulder
Description: 
Westbound corridor from I-405 to the Evergreen Bridge; 2.7 mi with several interchanges
Date Implemented: 
1970s
Date Terminated: 
N/A
Operational Information
Allowed Vehicles: 
Buses and 3+ carpools
Operational Hours: 
24/7
Conditions: 
Can travel at same speed as other lanes
Maximum Speed: 
Same as other lanes; posted speed limit
Geometric Features
Cross Section Details: 
Shoulder Width: 13'-14'
Treatment at Interchanges: 
Shoulder users must merge back with regular traffic at interchanges
Handling of Inlets: 
Limited physical improvements were needed
Performance Measures
Operational Effectiveness: 
Eliminates weaving movements for buses
Safety Evaluation: 
Safety Record has been reported as good
Other Impacts: 
Motorist compliance has been good
Incident Reponse
Responsibilties: 
Automobile trouble is encouraged to exit freeway. Tow trucks are strategically stationed to clear shoulder
Operational Experience: 
Motorist compliance has been good