Starting in January 2021, we will add an automated photo enforcement system on the Low Bridge that will supplement existing enforcement by police

The Low Bridge. Photo Credit: Tim Durkan.

We need to keep the West Seattle Low Bridge clear for emergency vehicles, freight, and transit. 

In October, we announced that automated photo enforcement would begin on the Low Bridge (also called the Spokane St Swing Bridge) as early as January 2021. The West Seattle High-Rise Bridge remains closed. In this blog, we’ll discuss how photo enforcement will work and what you can expect. 

Signs alerting Low Bridge users about photo enforcement were installed last month, and new cameras will be installed Thursday, December 10.  

On Thursday, December 10, the Low Bridge will be reduced to one lane (so that vehicles can travel in only one direction at a time) from as early as 9 a.m. to as late as 3 p.m. A flagger will be present to guide people driving. Please be aware that the flagger is present and be prepared to stop if you are driving in either direction.

When the photo enforcement system is activated, these cameras will take pictures of vehicles’ license plates when they cross the Low Bridge between 5 a.m. and 9 p.m. each day, in either direction. Photos will be taken of the back of the vehicle only to record the license plate number and will not be taken of the person driving. The photos are prohibited from being used for any other law enforcement action.  

The system will then cross-reference those license plate numbers with a database of authorized users to identify whether a vehicle is allowed to use the Low Bridge at that time. Unauthorized vehicles are subject to a $75 citation for every trip across the Low Bridge. 

The Low Bridge is only one lane in each direction (two total lanes), compared to seven total lanes that previously accommodated traffic on the High-Rise Bridge at its widest point. If all vehicles that previously used the High-Rise Bridge tried to use the Low Bridge, the resulting congestion and delay would block the efficient movement of emergency response, people, and goods. 

Low Bridge authorized users 

A vanpool with a bike attached to the back about to cross over the West Seattle Low Bridge.
Low Bridge authorized users include vanpools, shown here. Photo Credit: Tim Durkan. 

Authorized users include emergency, transit, and freight vehicles, as well as select maritime, government, and West Seattle business vehicles performing nearby work functions. Access to the Low Bridge will be allowed for specific vehicles (linked to license plates) rather than placards, which are currently in use. The table below outlines who is and is not authorized to use the Low Bridge.


Who CAN Use the Low Bridge

  • Emergency vehicles   
  • Transit vehicles (King County Metro buses and school buses) 
  • Freight vehicles 
  • People walking, rolling, using a scooter, or biking 
  • Employer shuttles 
  • Vanpools 
  • Pre-authorized vehicles*  
  • Personal vehicles at night (from 9 p.m. to 5 a.m. daily) 

Who CANNOT Use the Low Bridge

  • Ride-sharing vehicles, including taxis, Uber, and Lyft
  • Personal vehicles, including motorcycles, during the day (from 5 a.m. to 9 p.m. daily) 

*Pre-authorized use is limited to select maritime/industrial vehicles proximate to Harbor Island, International Longshore and Warehouse Union vehicles, and West Seattle business vehicles. 


Photo enforcement has many benefits and efficiencies.  

By automating the system, we can use fewer police officers on-site, meaning they can attend to other needs and decrease in-person stops during the COVID-19 pandemic. It also makes enforcement more uniform and objective, eliminating the visual guesswork about who is or is not authorized to use the Low Bridge from 5 a.m. to 9 p.m. daily. As a reminder, all vehicles are allowed to use the Low Bridge overnight between 9 p.m. and 5 a.m. daily.  

Photo enforcement allows us to specify which vehicles are authorized to use the Low Bridge at specific times of the day. This may help us better align with travel demand to maximize efficiency of the limited roadway. 

Seattle already uses photo enforcement to promote safety at intersections by citing people running red lights and in school zones by citing people driving too fast near children. A similar photo technology will be used to enforce authorized use of the Low Bridge in January, due to a new law passed by the state legislature. 

Restrictions on the Low Bridge help ensure smooth movement of emergency vehicles, freight, and transit for everyone’s basic health and safety. An automated system will allow us to more seamlessly provide a clear path for authorized users and enforce rules fairly and consistently. 

Unauthorized vehicles are subject to a $75 citation for every trip across the Low Bridge. 

When photo enforcement is operating, the registered owner of an unauthorized vehicle will receive a notice of infraction in the mail within 14 days. Citations can be issued for both directions of travel on the bridge. 

Instructions for paying or contesting the citation are found on the citation itself, along with contact information. Citations are $75 maximum, and, as with other citations, the Seattle Municipal Court provides an option for community service in lieu of paying the fee and zero-interest payment plans to reduce financial hardship to qualifying individuals.   

It is currently illegal to make an unauthorized crossing, regardless of the status of the new photo enforcement system. Unauthorized Low Bridge users can be cited by Seattle Police Department officers that may be on-site. The new system is supplementary, like the use of red light cameras.  This means there is no official warning period for photo enforcement. 

Since the West Seattle High-Rise Bridge closed in March, we have restricted Low Bridge access in order to preserve mobility for emergency vehicles, transit and freight.  

The West Seattle Low Bridge viewed from above. Cars and people biking and walking are shown. This photo was taken prior to the closure of the West Seattle High Rise Bridge.
The Low Bridge. Photo Credit: SDOT Flickr. 

This access was provided earlier this year using a placard system and are now shifting to photo enforcement as described above. We’re working with a subcommittee to inform this dynamic Low Bridge Access policy.  

This subcommittee currently consists of seven members who provide perspectives across these subgroups: West Seattle businesses, the maritime industry, and healthcare workers/patients. We recognize that not everyone who wants to use the Low Bridge is represented on the subcommittee, so we will continue to identify interested user groups for discussion with the subcommittee in the coming months.  

We will continue to monitor operations as photo enforcement begins. Our subcommittee is helping us implement this new enforcement tool now, and is in dialogue with us about ways to expand and restrict the authorized user pool to ensure that Low Bridge traffic keeps flowing and to keep everyone as safe and connected as possible. 

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