Why LA is lowering (and raising) speed limits on city streets

Reducing speed limits on city streets coupled with enhanced law enforcement is a recognized, straightforward tool for reducing traffic fatalities. Generally, raising speed limits is not. But the city of Los Angeles faces an unusual set of circumstances that at least in part reflects state legal requirements.

Effective traffic management and roadway safety are critical elements in smart city mobility. We're sharing the story below because other cities may be in the same or a similar situation to the one Los Angeles is trying to work with. And for those cities, there are very likely valuable lessons to be learned. — Doug Peeples

Earlier this week Los Angeles Mayor Eric Garcetti announced new speed limits for 71 city streets as part of the city's Vision Zero initiative to reduce traffic fatalities. The new limits will be accompanied by enhanced traffic law enforcement from the Los Angeles Police Department.

"Nothing is more important than the safety of Angelenos — and every decision we make about our streets should be with their well-being first in our minds," the mayor said. "These new, enforceable speed limits will help make our streets safer and easier to travel for everyone who uses them."

The backstory
As the mayor's office explained in a news release, California law requires cities to conduct speed surveys before they can set and enforce speed limits. The surveys involve a lot of data gathering: average driving speeds, collision frequency, roadside conditions, business and residential density and bicycle and pedestrian safety. And they're required every five to 10 years.

But a lot of the city's surveys expired during the economic recession, and the Los Angeles Department of Transportation had to conduct updates before it could adjust speed limits and enforce them to coincide with the city's Vision Zero goals.

Vision Zero is a multi-national project focused on eliminating road-related fatalities and serious injuries. Los Angeles has a goal of no fatalities on city roadways by 2025.

After updating its surveys the city got the go-ahead to set new speed limits. According to the mayor's office, enforceable speed limits are now active on almost all of the city's High Injury Network, those streets with high rates of serious and fatal collisions — and LAPD has earmarked additional overtime money to enforce those limits.

As of now about 68% of the city's streets have enforceable speed limits and updated speed surveys are expected to be completed by the end of the year.

The recent survey updates left most street speed limits unchanged, but a total of 94 miles of city streets now have increased speed limits while 53 miles of streets have lower limits. The increased speed limits are the results of the new survey findings and are expected to relieve traffic congestion in those areas somewhat, and will be among the areas getting increased law enforcement.

How much congestion can be reduced with that approach is hard to say because the Los Angeles region is growing — and while voters approved funding to increase transit capacity and improve highways in 2016, they remain reluctant to give up their cars. And, as we noted earlier, the city has the most congested streets in the world, according to the 2017 Global Traffic Scorecard compiled by traffic analytics firm INRIX.

Doug Peeples is a Portland, Oregon-based writer specializing in technology and energy. Follow @smartccouncil on Twitter.