Los Angeles Mayor Eric Garcetti is committed to Vision Zero, a project to eliminate traffic fatalities by 2025 through street system management. Building on its vision of safety as the most important criterion for transportation investments, the City Council has adopted Mobility Plan 2035, a 20-year initiative to remove automobile lanes and make more room for bus and bike lanes. The goal is to save lives by improving pedestrian and cyclist safety. But it might cost lives instead.

Eliminating automobile lanes would increase congestion, slow emergency response times and endanger lives.

The city’s environmental impact report admitted that Mobility Plan 2035 would cause “unavoidable significant adverse impacts” on automobile congestion. It would leave 36 percent of intersections heavily congested (graded F) during evening rush hours—double the current proportion and far higher than the 22 percent forecast in absence of the plan. Motor vehicles trapped in gridlock cannot clear the way for an ambulance or fire truck responding to an emergency call.

The worsened congestion would be especially life-threatening in cases of sudden cardiac arrest, which requires rapid medical intervention to save a life. Even delays measured in seconds can have deadly consequences. Mayo Clinic physician Roger White told USA Today: “A one-minute decrease in the call-to-shock time increases the odds of survival by 57 percent.” Shortening the response time by three minutes improves a victim’s chance of surviving almost four-fold.

In 2003, USA Today estimated that a 14 percent increase in survival rates for sudden cardiac arrest in Los Angeles would have saved 104 additional lives (out of 739 incidents)—greater than the number of pedestrians killed in the city in some years. Therefore, even if Mobility Plan 2035 were to eliminate all such fatalities, an impossible goal, more Angelenos could die from delayed emergency treatment. Factoring in the delays for noncardiac emergencies would only worsen the body count.

Economist Randal O’Toole, who has written extensively on urban transportation, summarized the tradeoffs: “Studies have shown that for every pedestrian whose life might be saved by traffic calming, more than 30 people are likely to die due to delays in fire trucks and paramedics.”

And it could be worse. Ronald Bowman, former project director for the National Bureau of Standards laboratory in Boulder, Colo., found that one traffic mitigation plan there cost 85 lives for each one saved.

The Los Angeles City Council failed to consider the dangerous delays its recommendations would cause, despite a mandate that its decisions reflect “substantial evidence.” Mobility Plan 2035 could cost many more lives than it would save. The failure to assess the risks it poses is totally irresponsible. Until emergency responder effects are thoroughly investigated, the plan should be put on hold, not on a pedestal.