What do you think of Level of Service?

San Francisco Planning and Urban Research Association (SPUR) yesterday posted a discussion about traffic Level of Service. Level of Service or LOS is the metric used by planning agencies when designing road networks. Level of Service “A” is the mythical world of car advertising, with letters progressing to LOS “F,” which is near gridlock. Many city streets in the Bay Area are generally somewhere between these two extremes.

Willow Road morning traffic

Unfortunately, LOS has historically measured only one type of traffic — that of private automobiles — with no evaluation of what improved vehicular movements means for those who don’t drive. Before California Governor Jerry Brown signed SB 743 into law last year, the California Environmental Quality Act even required mitigation for projects that reduced vehicular LOS. If a new bike path or mid-block crosswalk measurably reduced vehicular throughput, California’s environmental protection law required the possible addition of traffic lanes to make up the difference.

The Santa Clara Valley Transportation Agency (VTA), which does transportation planning for the Silicon Valley region, pointed to the SPUR discussion on Twitter today and received a number of responses about LOS.

LOS Level of Service Tweets

What’s your opinion? Is it time to reconsider Level Of Service as the only measure of transportation effectiveness?


  1. Level Of Service is fundamentally flawed in that the highest attainable score is based on providing costly infrastructure to allow the least competent of motor vehicle operators to reach the highest speeds in the shortest distance. The results are disastrous to both budgets and living things. This transportation model should stayed where it belonged on our interstate highway system and it never, ever should have been applied our city streets.

  2. F – Bikes not allowed (freeway)
    E – No bike lanes & 45 mph traffic
    D – Bike lanes on expressway / No bike lane and 35 mph speed limit
    C – Bike lanes on arterial / No bike lane on side street
    B – Multi-use path / Low-traffic side-street with 20 mph speed limit
    A – Curb-protected bike lane / Off-street path with separate path for walkers

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