“What you measure is what you get,” the saying goes.
That’s certainly true for transportation policy. And for a very long time one metric has reigned supreme on American streets: “Level of Service,” a system that assigns letter grades based on motorist delay. Roughly speaking, a street with free-flowing traffic gets an A while one where cars back up gets an F.
Level of Service, or LOS, is what traffic engineers cite when they shut down the possibility of transitways or bike lanes. It also leads to policy decisions like road widenings and parking mandates. Even environmental laws are structured around the idea that traffic flow is paramount, so they end up perpetuating highways, parking, and sprawl. Because if the top priority is to move cars — and not, say, to improve public safety or economic well-being — the result is a transportation system that will move a lot of cars while failing at almost everything else.
The good news is that there’s a growing recognition inside some of the nation’s largest transportation agencies that relying on LOS causes a lot of problems.
Just last week, the state of California introduced a new metric to replace LOS in its environmental laws. Instead of assessing how a building or road project will affect traffic delay, California will measure how much traffic it generates, period. Car trips, not car delays, will be the thing to avoid. This is likely to have the opposite effect of LOS, leading to more efficient use of land and transportation infrastructure.
Change is afoot at the federal level too. Officials at the Federal Highway Administration are looking at how they can spur changes like California’s LOS reform in other places.