An End to LOS in Pasadena

On November 3, Pasadena’s City Council voted unanimously to ditch the car-centric measure of mobility called “level of service,” or LOS. The policy change was developed and proposed by the staff at Pasadena DOT and is a critical element of Pasadena’s efforts to become a more environmentally-friendly city by encouraging multi-modal transportation, and denser, mixed-use development downtown. Pasadena’s local complete streets advocacy group, Pasadena Complete Streets Coalition (PasCSC), lobbied for this change as a necessary step in making the city’s streets safer and more user-friendly for pedestrians, bicyclists, and transit users. The state of California is currently reassessing LOS and working on its own statewide multimodal metric, but to my knowledge Pasadena is the first city in Southern California (though certainly not the last) to break from the old LOS standard.

For the policy wonks, LOS was developed by traffic engineers decades ago as a means of measuring the increased automobile traffic that often comes with the growth of cities. It made sense in an era when cities were being redesigned around the automobile and it was assumed that everyone would—and should—drive. It makes far less sense when cities are trying to reduce their carbon footprint, automobile pollution, and encourage alternative modes of personal mobility. Providing for the convenience of automobile mobility as the only measure of transportation quality had the unintended consequence of creating what is known as “induced demand” as wider roads encouraged more driving, more driving begat more auto-centric development, which, under LOS, mandated wider roads, ad infinitum.

One of the downsides of LOS has been that it measured the transportation impact of property development and road use solely by its impact on automobile wait times at intersections. Put another way, pedestrians, bicyclists, and transit users didn’t count, so their needs usually went unmet under the LOS rubric. A short wait time for cars at an intersection would, for example, receive an ‘A’ grade, while a longer wait time for cars would receive lower grades. Pedestrians who had a long wait at a traffic light and then a dash across the street to beat the short crossing signal were not counted under LOS. A bus with 25 passengers counts as much as a single occupancy automobile under LOS. A bike lane that might slightly reduce road capacity for automobiles would be D.O.A. under LOS, on the assumption that it might make drivers wait a few seconds longer at a stoplight, triggering a failing LOS grade. Never mind that more people would be willing to leave their cars at home if they had safe, convenient alternatives, LOS meant drivers, and only drivers, counted. Moreover, the widening of roads to achieve a good LOS score often resulted in unused road capacity during off-peak hours and has also been shown to induce higher automobile speeds and deadlier collisions. The ‘S’ in LOS thus stood for service to motorists only, and reflected the domination of streets by cars in the late 20th century. The new standard reflects the idea that cities should measure the movement of people, not just cars, when judging the impact of development.

The new standard uses a mix of Vehicle Trips (VT) generated, Vehicle Miles Traveled (VMT) per capita, access to alternative modes (walking, biking, transit) of transportation, as well as LOS. The new measure also provides that mitigation of the traffic impact of development can include funding for alternative modes of transportation, whereas previously a developer would be required to provide more parking or road-widening. Pasadena DOT staff believe that the new measure provides a fuller picture of the multimodal reality of modern city mobility and give the city the flexibility to encourage multi modality, safety, and sustainability.

Pasadena still has a long way to go to achieve its complete streets vision, but it is gratifying to see the city take one more step toward that vision.