Skip Top Navigation

SR 520 - Floating Bridge and Landings: Drawspan Information

Key resources for drivers and boaters

Sign up for text message or email alerts for drawspan openings.

Quick reference guide (pdf 360 kb) to drawspan opening times.

To request an opening of the SR 520 drawspan for vessels over 45 feet tall, call 206-440-4490.

The SR 520 Bridge Information page lists scheduled SR 520 drawspan openings.

More info on WSDOT movable bridges

SR 520 marine information

Updated: Aug. 22, 2014

Visit the SR 520 Bridge Information Web page for currently scheduled drawspan openings. 

SR 520 Navigation Channel Restrictions

As of Saturday, April 19, the western-most pontoon is moored in its permanent location, 50 feet north of the existing bridge near Madison Park. The pontoon is located on the west side of the existing 206-foot-wide channel, reducing the channel width to 120 feet. The narrower channel is marked by traditional red and green buoy channel markers. This new configuration (pdf 596 kb) will be in place until additional pontoons are joined with Pontoon A. 

A new exclusion zone is also active immediately north and south of the pontoon. This off-limits zone is marked by six white buoys and a sign on each end of the pontoon. Please note, the white buoys represent the locations of the anchor lines and it is dangerous to pass between the sign and the buoys. 

Due to construction activities, the east navigation channel under the SR 520 bridge is currently obstructed. The channel will be cleared during specific weekends and holidays as listed below.

Note: When the channel is open, it is operating with reduced clearance. Navigational clearances are higher on the east side of the channel, but obstructions north of the channel reduce the navigational height to 58 feet. Boats taller than 58 feet should not attempt to navigate through the channel.

If your vessel, mast or other aerial equipment is over 58 feet tall and cannot be lowered please follow the instruction below to request a drawspan opening.

SR 520 drawspan operations for boats over 45-feet-tall

Hours Weekdays Weekends
Midnight - 6 a.m. Drawspan opens any time with minimum 2 hours advance notice Drawspan opens on the hour and half-hour with 2 hours advance notice
6:30-10 a.m.
(Morning peak commute)
No drawspan openings
10 a.m. - 2:30 p.m. Drawspan opens on the hour and half-hour with 2 hours advance notice
3-7 p.m. (Afternoon peak commute) No drawspan openings
7 p.m. - Midnight Drawspan opens any time with minimum 2 hours advance notice

Drawspan opening requests
To request an opening of the SR 520 drawspan for vessels over 45-feet-tall, call 206-440-4490.

To keep the bridge in good working order, WSDOT may need to suspend drawspan openings if wind speeds exceed 30 miles per hour. Drawspan openings will resume as winds subside.

2014 special dates
Both east and west navigation channels beneath SR 520 will be open on the following dates in 2014.

  • 9 a.m. Thursday, May 1 to 11:59 p.m. Sunday, May 4 (Opening Day of Boating Season) 
  • 9 a.m. Friday, May 23 to 7 a.m. Tuesday, May 27 (Memorial Day weekend) 
  • 6 p.m. Thursday, July 3 to 7 a.m. Monday, July 7 (Independence Day weekend) 
  • 9 a.m. Thursday, July 31 to 5 a.m. Monday, Aug. 4 (Seafair weekend) 
  • 9 a.m. Friday, Aug. 29 to 5:00 a.m. Tuesday, Sept. 2 (Labor Day weekend) 
    The east and west navigation channels will be congested during this time. Please review the illustrations showing the configuration of the nav channels during Labor Day weekend. (pdf 4.5 mb)

Note to boaters: WSDOT, and the region’s commuters, appreciate your flexibility in working with us to operate the SR 520 drawspan. Help us keep boats and traffic sailing by providing as much lead time as you can and letting us know if you have flexibility in the timing of your request. The chart provides information on the minimum notice required of boaters in order to open the drawspan.

You can also print a quick reference guide (pdf 360 kb) with this key drawspan opening information.

SR 520 drawspan hours posted
After consultation with the U.S. Coast Guard, hours for drawspan openings on the SR 520 bridge have been adjusted.

Openings are prohibited during peak commute times of 6:30-10 a.m. (previously 6-9 a.m.) and 3-7 p.m. (previously 4-7 p.m.). Also, boaters will be required to provide two hours notice at all times before the drawspan will be opened, rather than just one hour during certain times of day.

WSDOT used traffic data and comments from the traveling public to request that the Coast Guard alter the hours and rules for drawspan openings.

These updated rules took effect for drivers 7 a.m., Thursday, July 5, 2012.

Why make this change?

On April 1, 2012, construction barges working to replace the vulnerable SR 520 floating bridge created a work zone within the SR 520 eastern navigation channel that blocks boating traffic.

The eastern navigation channel has a 55- to 64-foot clearance, but is now blocked by construction equipment.

As a result, Coast Guard rules require WSDOT to open the SR 520 floating bridge drawspan to allow passage of boats over 45 feet tall with advance notice. We will not open the drawspan during weekday peak commuting hours.

The western highrise will remain open throughout construction and has a 45-foot clearance.

What do drivers need to know?

WSDOT will work with boaters to minimize effects on the traveling public.

Before construction, bridge closures and drawspan openings were allowed only 9 p.m. to 5 a.m. weekdays and on weekends with two hours notice with the understanding that the west channel allowed 45-foot-tall boats and the east channel allowed boats ranging from 55 feet to 64 feet.

Also according to Coast Guard rules, both the west and east navigation channels will be open on several major events and holidays when boat traffic is heaviest.

Those dates include opening day of boating season, Memorial Day weekend, Independence Day, Seafair weekend and Labor Day weekend.

Sign up to receive text message or email updates about drawspan openings. Openings are also posted on VMS signs (pdf ) on highways leading to SR 520.