The benefits of removing stop lights

A traffic light in Detroit

In the 1990s, the City of Philadelphia 800 traffic lights. Traffic flow improved and accidents declined by 26 percent in these intersections. 

Recently, Wayne State researchers that Detroit remove 460 signals, or 30 percent of its total inventory. And that figure may underestimate removable signals, the researchers note.

Last year at the Congress for the New Urbanism, British street designer and "shared space" advocate Ben Hamilton-Baillie urged CNU members to “take out all of the traffic signals in every city in the US — it would be a very simple thing to do.”  CNU members don't have the power to unilaterally remove stop lights, and most of them wouldn't go so far as Hamilton-Baillie recommends—but his point that traffic signals are often not necessary and damaging to urban places has growing adherents.

Planner Jeff Speck, author of Walkable City and former Director of Design of the National Endowment for the Arts, is a big proponent of removing traffic signals. Cedar Rapids, Iowa, has based on Speck's downtown revitalization plan. Four-way stops improve traffic flow because automobiles don't have to come to an extended stop and wait while signals change, Speck points out. For pedestrians, four-way stops are much better—because every automobile has to come to a complete stop and traffic is calmed. 

According to the Cedar Rapids Gazette:

Speck said doing away with most of the downtown traffic signals in favor of four-way stops would make for a "dramatic change" to the downtown. Such an arrangement favors pedestrians — "The pedestrian is king" in the setup, he said — and he said motorists will prefer it because they don’t have to idle at traffic signals waiting for lights to change.

Cedar Rapids could save enough money by removing traffic signals to pay for other pedestrian improvements, Speck notes. Each signal costs upwards of $8,000 a year, the Wayne State researchers report. Detroit could save $3.7 million a year by removing unnecessary traffic signals, they say. 

While traffic signals are useful and necessary in certain circumstances, they can also have an insidious impact on walkability. They encourage speeding through intersections, which is deadly for pedestrians. They lead to more complex intersections with turning lanes that increase crossing distance. Each additional foot of width makes a street more difficult for pedestrians to cross. 

Increasingly complicated traffic signals were installed across in the US as part of raft of pro-automobile policies and expenditures such as wider lanes, one-way streets, much bigger intersections, removal of street trees, and concentration of traffic on arterial thoroughfares. These policies elevate driving over other modes of travel and reduce safety, harm health, and hinder economic development, . Traffic engineers used a "rule of thumb" that one traffic signal should be installed for every 1,000 residents, notes . 

Based on what we know now, the wisdom and efficacy of such a policy is open to serious question. CityLab offers four reasons to remove traffic signals: Cost, traffic flow, safety, and equity. Vehicle miles per capita has been declining, especially in walkable cities. Signals may have been installed under the assumption that traffic volume would continually grow. 

Walkability advocate Jay Walljasper removing traffic signals at "less busy" intersections. "Motorists rocketing through intersections to avoid a red light is one of the most common--and dangerous--causes of speeding," he says.