The city of San Francisco in 2008 proposed adding a rapid bus lane to its streets. It took nearly a decade for the project to pass environmental review – because it would slow down cars.

“It was a very backward result for a very transit-friendly project,” said Ethan Elkind, director of the climate program at the University of California Berkeley Center for Law, Energy, and the Environment. “But that’s level of service for you.”

Level of service is a metric used nationwide to evaluate new city projects based on how much congestion they create. But with Americans driving more than ever, and with transportation accounting for the largest share of carbon emissions in the U.S., studies show that this decades-old traffic mitigation measure imposes standards that actually incentivize more driving. And a newly effective California law makes it the first state to do away with the measure entirely.

“Level of service is misguided, bankrupt, and dangerous,” said University of Iowa law professor Gregory Shill, author of a March 2019 study examining how some policies incentivize driving. “It’s ‘level of service’ for people alone in their cars who want to drive further and faster.”

Level of service … ‘like using a rototiller in a flowerbed’

Level of service was introduced in the 1960s as a way to measure, and mitigate, vehicle congestion. The standard penalizes new transportation or development projects that inhibit local traffic flow. The approach makes a kind of sense: Nobody wants to sit in traffic, and idling cars puff harmful emissions. But policy experts say it never should have been the only standard.

“It’s a strictly one-dimensional metric,” said Gary Toth, senior director of transportation initiatives at the nonprofit Project for Public Spaces. “It treats roads only as a conduit for fast driving.”

By putting speed first, the metric discourages more climate-friendly forms of transportation. Level of service assessments favor widening roads, increasing speed limits, and adding turn lanes. At the same time, they inadvertently penalize adding bus lines, bike lanes, and even sidewalks.

Toth said this is like “using a rototiller in a flowerbed”: By cutting all obstacles to fast travel, we wind up destroying our streets.

Worsening a problem meant to be solved?

Multiple studies, such as 2017 research published in the Transportation Research Record, show that widening roads can in fact cause congestion. To explain this phenomenon, transportation researchers borrow economists’ theory of “induced demand”: When something is available, people are more likely to use it.

“By requiring people to drive, [level of service] creates the very problem it’s trying to solve,” said Emily Mangan, director of climate policy at the policy organization Transportation for America.

Level of service standards could also indirectly add 50 cars to an already-busy intersection – and potentially discourage other development. But a proposal for developing single-family units on undisturbed landscapes would sail through level of service approval – because there’s no existing traffic to disrupt.

“All incentives go to building a subdivision out in the middle of nowhere,” said Elkind. “It’s really hurting housing projects where we most need them.”

In California, level of service isn’t just a traffic standard – it’s embedded in the California Environmental Quality Act. That means cities like San Francisco find their plans out of compliance with environmental standards until they make room for more cars.

Nothing did more harm to the California environment than the transportation standards in the California Environmental Quality Act, said Jeffrey Tumlin, transportation director of the San Francisco Metropolitan Transit Authority.

Laying the groundwork for repeating past mistakes

In 2013, then-Governor Jerry Brown signed SB 743, mandating that by January 2020 all California cities transition to a new metric: vehicle miles traveled. That VMT approach assesses projects based on how many total vehicle miles they add to the world’s miles driven. The fewer miles added, the higher a new project scores. It rewards dense, walkable streets and urban infill projects that put people near transit. The Environmental Protection Agency has used it as a standard to reduce transportation greenhouse gas emissions.

“Sprawl developers aren’t evil. They did what they could based on the standards in place,” said Toth. “In California, they’ll get to use their cleverness to minimize car travel.”

Ethan Elkin and colleagues at U.C. Berkeley are working on policy strategies to help implement the change statewide. One such strategy would create a “VMT mitigation bank” system, requiring developers of sprawl projects to fund climate-friendly ones in other areas.

But Elkind said he worries that for growing cities like Boise and Phoenix, the incentives to drive are already entrenched.

“Even if California tries to right the ship, the fastest growing places in the United States are replicating the ‘LOS’ model,” he said. “We’re laying the groundwork to repeat these mistakes over and over again.”

Brett Simpson is a freelance audio and print reporter and master’s candidate at the U.C. Berkeley Graduate School of Journalism.