Reducing Single-Occupant Vehicle Trips - What & Why

What's Happening Now?

In January 2019, the City Council passed and the Mayor signed Ordinance 125757, which amended chapter 23.52 of the Land Use Code. This sets new "level-of-service" standards for the City's transportation network. Level-of-service standards help us measure traffic congestion within Seattle.   

Previously, level-of-service standards compared the volume of automobiles using city streets during peak times to the capacity of those same streets.

The new level-of-service standard is the percentage of trips made by single occupancy vehicles (SOV) within different sectors of the city.  Periodic travel surveys by the Puget Sound Regional Council will let us know how we are doing.

The new level-of-service standards are consistent with Comprehensive Plan goals to encourage different personal transportation choices such as taking transit, bicycling, and walking more often. The standards make the best use of our limited available street capacity, increase the ability to move more people efficiently, and reduce reliance on single occupancy vehicles (see linked graphic - street efficiencies gained).

The new code helps ensure that new development projects above a certain size contribute fewer single occupancy vehicle trips using the City's roads. The requirements apply to:

  • Residential uses with more than 30 dwelling units or sleeping rooms
  • Non-residential uses greater than 4,000 square feet of gross floor area
  • Non-residential uses in Industrial zones that have more than 30,000 square feet of gross floor area used for agricultural purposes, high impact uses, manufacturing, storage, transportation facilities, or utilities  

Within Urban Centers, Hub Urban Villages, and light rail station areas, these requirements are already met because transportation choices are quite efficient and support the City's transportation planning goals. Outside of these areas, new development must take steps upfront to promote more efficient travel choices, such as choosing to do one of the following:

  • Subsidizing transit passes
  • Providing nearby sidewalk and curb cut improvements
  • Limiting the amount of parking provided in new buildings
  • Including a mix of uses in their development  

The proposal includes a preliminary draft joint Seattle Department of Transportation (SDOT) and SDCI Directors' Rule that establishes the choices new developers and building owners will have. As of June 2019, SDCI and SDOT staff are still finalizing the Directors' Rule.

Project Benefits

The coming of more light-rail service in North Seattle in a few years will help boost the convenience and effectiveness of these transportation choices.  This should make a difference in how many vehicles are using our streets during peak hours.

We are asking developers to make choices about project location, design, and amenities that will make it easier to use and access transit and other alternatives to driving alone. 

The End Result

Our transportation system will benefit by moving more people with more efficient travel options to make better use of its overall capacity.  For those traveling on our streets, this will help avoid traffic gridlock, and ensure the system provides people with good options for moving around the city.

People will be able to move more safely in their neighborhoods with street, sidewalk, and bicycling system improvements.

People will be able to make efficient travel choices that save them money; the costs of driving and maintaining a vehicle are more expensive than other transportation options.