Vehicles pass over a recently installed speed hump on Hobart Gap Road in the township of Millburn, N.J., on Monday, April 5. Millburn is one of many towns around the country that have turned to speed humps to slow down traffic but have faced a backlash from residents opposed to their use. (Photo by Christian Yarnell/CNS)

After a 19-year-old died last October in a single-car crash in the wealthy suburban township of Millburn, N.J., many of the town’s 20,000 residents demanded action to reduce speeding on local roads. A few weeks after the accident, the township’s public safety committee met and quickly decided on a solution. Traffic-slowing speed humps were installed at eight different intersections around town, including on Glen Avenue, home to Millburn’s busy train station, which is where many commuters to New York City begin their trip.

While town officials claim the decision was in the works for a while, it seemed meant to satisfy residents alarmed by the accident. But it also triggered vocal opposition, leading to a tense public debate about  traffic problems.

Around the country, cities and towns worried about pedestrian safety and fed up with speeding cars on residential streets have increasingly turned to speed humps. Speed humps are like speed bumps at malls and in parking lots, but they are lower and therefore have a little less oomph. They are raised areas of pavement typically 12 to 14 feet in length and 3 to 4 inches high.

The humps are just one type of traffic-calming measure, which include traffic circles and electronic signs that display the speed of passing cars. Studies show that the humps do help lower traffic speeds. “We don’t have anything else as effective,” said Scott Batson, an engineer for the city of Portland, Ore., which has some 1,100 humps.

But as much as the humps please safety advocates, many residents in towns where they have been installed are equally frustrated by their unintended consequences, which range from inconvenience to increased noise to slowing the response time of fire trucks and ambulances.

Studies show that speed humps lower car speeds by 20 to 25 percent, according to the Institute of Transportation Engineers. The ITE also says that streets where speed humps have been added experience 13 percent fewer collisions and an average of 18 percent less traffic, depending on the alternative routes available. While research shows that lowering speeds generally reduces traffic fatalities, said Lisa Fontana Tierney, traffic engineering senior director at the ITE, there is no good evidence that speed humps actually save lives, because they are used on local roads, not highways, where fatalities are more common.

But advocates argue that the humps are ideal for local roads near highways, where there is a need to get drivers to slow down. “Speed humps are a great way to take people out of the highway mode that they’re in,” said Wiley Norvell, a spokesman for Transportation Alternatives, an organization in New York City that advocates for pedestrians and cyclists.

Local officials from places as disparate as New York City and Cobb County, Ga., have used speed humps to control traffic. Some cities, like Modesto, Calif., have a formal speed hump policy that allows residents to request humps by collecting a certain number of signatures. Paying for installation and upkeep can sometimes be a challenge. Memphis, Tenn., announced in December that it would allow neighborhoods that want speed humps to pay for them themselves because the city does not have enough money to keep up with demand.

But in many places, there has been a strong backlash against the installation of the humps. “It is an issue with emergency responders,” said H. Gene Hawkins, a professor of civil engineering at Texas A&M University and an expert on traffic control devices. The ITE estimates that each hump costs fire trucks up to 5 seconds, and ambulances up to 10 seconds. Hawkins said that manufacturers were trying to create specialized speed humps with grooves that would allow wider-wheeled emergency vehicles, but not cars, to avoid the hump’s impact.

Some residents also complain that speed humps increase noise and are just plain ugly. Craig Ott, 63, who has lived in Millburn for 28 years, said he was concerned about speeding cars near his house but thought putting in speed humps was the wrong solution. He has campaigned against them and believes that electronic radar signs would make more sense. “You come down that road at night, and it looks like you’re pulling into a hazardous waste place with all the warnings and colors,” he said.

Lezette Proud, 82, who has lived in part of Millburn Township since 1955, said the noise bothered her. “When you’re lying in your bed at night and the cars go over them, they go ‘kathunk,’” Proud said.

And of course many drivers do not like speed humps because they do precisely what is intended: force cars to slow down. Driving over them too fast can damage vehicles. Avoiding them lengthens drives and is inconvenient.

“Generally, we’re opposed to traffic calming measures,” said James Baxter, president of the National Motorists Association, which advocates for drivers and got its start in the 1980s in the fight against the 55-mph national speed limit. Baxter complained that drivers most affected by speed humps are often the least organized, since they frequently do not live in the communities where the humps are installed. “It’s a case where the squeaky wheel gets the grease,” he said. And too often, community residents are effectively just “trying to divert traffic to someone else’s street,” he added.

Opponents have pushed back in many communities. Bowling Green, Ky., decided in December to stop building speed humps in the wake of the public outcry against them. Officials in Hillsborough County, Fla., had to bring in an independent arbitrator last year to referee the argument between pro-hump and anti-hump residents in a Tampa suburb. An editorial in the St. Petersburg Times in December argued against the growing use of traffic calming measures, saying, “Our public streets, built to provide access and easy movement of traffic, are being turned into obstacle courses.”

Experts agree that speed humps are not a panacea and need to be designed by experts to be effective. “Where you get someone who’s not a traffic engineer saying, ‘Let’s put in something that will slow the traffic down,’ that’s when you get into trouble,” said Hawkins, the Texas A&M professor.

In fact, local residents are usually the driving force behind the installation of speed humps. “These are always reactive kinds of projects,” said Batson, the Portland engineer. While some residents push for the humps, a minority is usually opposed, Batson said. Portland addresses the potential conflict by requiring residents to vote before they are installed.

Such a vote might have saved Millburn a lot of trouble and expense. On March 16, after much public opposition to the humps and an investigation that found they violated the state’s design recommendations, Millburn’s township committee decided to remove five of the eight new humps. The $8,000 installation cost was lost.

“There needs to be community input beforehand,” said Timothy Gordon, Millburn’s business administrator, when asked what advice he would give to other towns considering speed humps. “If we made one mistake, that was probably it.”