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When Streets Go Bump
Slowing for Safety in Neighborhoods

Putting Controls in Place Many who dislike speed humps ask why localities do not just use stop signs instead. "Stop signs are for controlling right-of-way, not speed," said Tracy Wroe, a Montgomery County traffic engineer. "The assumption is that everyone will stop, but compliance goes down on low-volume residential streets." Moreover, studies show that from 11 percent and 25 percent of drivers do not even apply the brakes when approaching a stop sign. "Those are the ones you really have to worry about," Wroe said. What criteria are used to decide whether a street gets a speed hump or other calming device? While details vary by jurisdiction, all look at: The number of vehicles that exceed a safe and reasonable speed. The number of vehicles passing through in a peak hour. Whether the route is a major one for emergency vehicles. Whether the location works -- speed humps and tables are not placed within 200 feet of an intersection, on winding roads, near tops of hills or on steep grades. Community support -- all jurisdictions require proven community consensus, but the requirements range from 51 percent to 80 percent of households.

By Ann Cameron Siegal
Special to The Washingt on Post
Saturday, February 15, 2003

In Europe they call them sleeping policemen. Here, they are known as speed bumps, speed humps, speed tables or raised crosswalks. But whatever name they go by, those raised areas in the road are cursed as much as they are praised.

At public hearings where these "traffic calming" devices are debated, endless questions come up. How effective are they? What about emergency vehicles? What about noise? Do they affect adjacent property values? Consensus is rare.

Bethesda resident Harry Kranz, for example, calls them "abominations" and does not think enough consideration is given to how these devices affect the aged, ill or disabled.

Kranz, who recently had surgery, said speed humps made the drive home from nearby Suburban Hospital painful. He was still seething over an earlier painful experience when he was being transported by ambulance to the hospital.

" While the technician was attempting to insert an IV needle in my veins, the ambulance bumped over two blocks of humps," he said.

To D.C. Councilman Jim Graham (D-Ward 1), who says he generally favors all manner of traffic controls, speed humps are not perfect, but seem to be among the most effective and affordable ways to rein in vehicles that zip along residential streets.

" We come to this out of exasperation because we don't have the policing we need," Graham said. "If you live on a block with speeders, you're desperate."

Graham, who helped get a number of speed humps installed on Adams Morgan streets last year, said, "It's become great sport for residents to sit on their porches and watch cars grind their underbellies."

He has little sympathy for those who do not slow down as they approach the well-marked humps. "You fly over these at your own peril. . . . If they weren't there, those speeders might injure a child."

" It's a balancing act," said Tracy Wroe, a transportation engineer for Montgomery County. "We would love to find the thing that would make everyone happy and not engender so much emotion."

Do not confuse speed bumps with speed humps, traffic engineers said. Speed bumps are those narrow, three- to six-inch tall strips used in parking lots and apartment complexes, but not on public roads. Drivers must come almost to a stop to safely navigate them.

The speed humps and speed tables popping up on the region's roads are easier on cars and passengers. Both speed humps and speed tables have a rise of three to four inches and are the width of both lanes of traffic. The tables are flat on top while humps are rounded, giving a car a bit more of a jolt when crossing. The tables are usually 22 feet long, the humps 14 feet.

Studies published by the Washington-based Institute of Transportation Engineers show that tables reduce speed an average of 18 percent and humps an average of 23 percent.

In Alexandria, brick-colored speed tables are favored and are placed 300 to 500 feet apart. "The driver can see the next one and won't speed up," said Bob Garbacz, chief of the city's transportation division. The tables do not really affect people who are driving a steady, legal 20 or 25 mph, he said. "They're a gentle reminder to slow down."

An earlier experiment with portable rubber speed tables was disappointing. "They wore out rapidly and were not snow-plow compatible," Garbacz said.

Local jurisdictions said these structures cost $2,500 to $6,000 each, depending on design and material used. By requiring that neighborhoods requesting speed humps pay for them cuts down on frivolous requests, officials say, but it raises a fairness issue: Should poorer neighborhoods have to put up with speeders because they cannot afford to pay for speed humps? The cost is usually passed on to the broad base of taxpayers unless a deal can be struck with developers whose projects increase traffic.

For example, two years ago, nine $5,000 speed tables were installed on just over a half-mile of Alexandria's Russell Road, and six more on parallel Commonwealth Avenue. The cost was covered by the Patent and Trademark Office, which was moving into new office space nearby.

However, Anne Arundel County requires that residents who request the speed control devices cover part or all of the cost, depending upon detailed criteria. Calvert County is just beginning to establish procedures and is leaning toward setting up special taxing districts so that communities will share costs for requested speed humps.

" We haven't had a need up until now," said Terry Carlson, chief of Calvert's transportation bureau. A recent request from the Shores of Calvert community has drawn attention to the topic, though, and has highlighted how complicated the issue can become.

A radar unit placed on the main street of the 133-home Shores of Calvert neighborhood in July logged 2,600 vehicles trips in three days, with 57 percent exceeding the speed limit. However, the county's criteria of 125 vehicles per hour was not met. Plus, Carlson said, "We'd never install these on curving roads with limited visibility or on steep grades, both of which exist in that community."

Alexandria's Garbacz said potential reductions in emergency vehicle response time are always a concern. Studies have shown that time lost ranges from three to 10 seconds per hump for fire trucks and ambulances, a seemingly insignificant delay that can add up when there is a series of rises in the road.

Even though many emergency vehicle drivers say heavy traffic is a bigger problem, some residents say they fear that ambulances might be tempted to take circuitous routes to avoid speed control mechanisms.

Alexandria officials recently designed a slotted speed table that allows emergency vehicles to avoid the rise by straddling the center line. Several were installed last year on Monroe Avenue just west of Route 1. Emergency vehicle drivers seem to prefer them to other humps, but say it is sometimes challenging to line up on the slots, especially if cars have pulled off to the side of the speed tables.

There are other challenges to those who drive over these raised asphalt structures. Jim Reed, an Alexandria mechanic, said he has seen numerous problems from when cars and snow plows go over the higher ones.

The speed tables can sometimes pull the splash shields off the bottom of late-model Volkswagen Bugs, Reed said.

Gary Birch, a firefighter with Engine 21 in Adams Morgan and himself the owner of a VW Beetle, agreed that in vehicles such as his it is important to take speed humps extra slowly. Gesturing toward one of the new speed humps on Lanier Place, a narrow one-way street that runs in front of the firehouse, Birch said, "Low-riders can't get over those. I saw one driver back up when he came to that hump" -- the whole way back down the street.

Some residents who live near speed humps say that the jackrabbit starts and stops that they prompt drivers to make are annoying. Al Kayatta said that when his family moved to Alexandria's Russell Road in 1987, "we knew what the situation was," referring to the busy north/south thoroughfare the road had become. "But we never bought into speed humps," which he said create considerable noise.

Kayatta's wife, Vicki, said: "Cars come up, slam on the brakes, then gas it as they get to the rise."Dora Ferina, a 19-year resident of Kingsley Boulevard in Vienna, had a similar reaction to the speed hump placed in front of her home in July. "I was one of those who carried petitions around to get these put in," Ferina said. She found little neighborhood opposition, as the road had become a speedway between Nutley Boulevard and Park Avenue, with many people using it to cut through to Tysons Corner.

Now, although she says the humps have helped cut down on speeders and that she would do it all again, she does have a twinge of buyer's remorse. There were some things the community had not fully considered.

" This is a major route for several schools, and school buses make a terrific noise in the mornings as they go over the humps. It wakes me up," Ferina said.

Second thoughts are not uncommon after the installation of speed humps. One speed hump on Kingsley Boulevard has already been removed because of residents' complaints.

In the early 1990s, Montgomery County saw a proliferation of speed humps when just about anyone who asked for one got it. In 1998, when the county had 1,100 speed humps on about 300 streets, a moratorium was placed on new humps.

Now criteria have been tightened. Requests and evidence of a demonstrated need must come from the president of the neighborhood association, or lacking that, from a local traffic committee representing several streets. Then, 80 percent of residents on the street have to concur, as do 50 percent of residents on adjoining streets who have no other way out.

Do speed humps affect property values? To read the myriad anti-speed-hump Web sites, you would be convinced they reduce a home's worth. However, in interviews with 15 long-term real estate agents in four jurisdictions, not one said they make a difference. The usual response was, "I've never had a client mention them one way or the other."

Mary Wharton, of Century 21 New Millennium in Alexandria, said: "People hesitate to buy on busy streets anyway, so these just show them how seriously Alexandria takes traffic concerns."

Whether speed humps cut down speeding or merely divert scofflaws to other residential roads is another recurring debate. Reports from the Institute of Transportation Engineers show the average number of vehicles per day is reduced by 22 percent with speed humps and 12 percent with speed tables, depending on alternate routes available.

Kranz, the anti-hump Bethesda resident, worries about a domino effect. "When traffic drops drastically on these humped-up streets, where does it go?" he asked rhetorically in a letter to the Gaithersburg Gazette. "It goes on other nearby streets . . . and may lead residents on those other newly burdened streets to ask for speed humps."

Engineers keep looking for less onerous solutions to the speed problem. One new device, the Dunlop Transcalm hump, is being tested in Britain. These rubber humps are filled with air and have a speed-sensitive valve. When a car moving at a slow speed crosses the hump, the valve opens and releases air, deflating a bit. That means those traveling at or under the speed limit get a softer ride. When cars cross at high speeds, the valve remains closed, leaving the hump as hard as one made of asphalt.

There are problems, though. The Transcalm hump reportedly costs about the same as traditional humps in Britain, (4,000 pounds, or about $6,000) but has a lifespan of just three to five years.

Some communities, such as Cheverly, have tried a combination of traffic-calming measures. Curb bump-outs and raised crosswalks were recently installed along a mile of Cheverly Avenue. While several residents said there's been a marked reduction in speed through their neighborhood, Charles Wilson has primarily noticed the loss of hubcaps as vehicles collide with the new bump-outs, as well as a marked decrease in available parking spaces.

" People don't slow down whatsoever," he said.

The obvious, cheapest solution, traffic officials said, is for drivers to pay attention to posted speed limits.

 

 

 

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