Easy-to-miss radar boxes give police heads up on where speeders have been
Since 2007, Manchester has been deploying two radar devices called Speed Sentry that count vehicles and record their speeds as they pass by.
About the size of a case of beer, the devices are easy for drivers to miss, but Speed Sentry won't miss any vehicle within about 500 yards of its location. And unlike speed board trailers, which flash a vehicle's speed in an obvious effort to alert the driver, each 18-inch-square, 12-inch-deep Speed Sentry box is mounted on the metal post beneath a stop sign.
Here's how the process works: Police receive calls, letters or emails from residents complaining about speeders along their street. Police mount a Speed Sentry on a stop-sign post in the area. Data is collected over a few days, downloaded, and fed into a program at police headquarters.
Instead of a police officer waiting all day to write seven tickets, police can use the radar information to patrol for two hours and write the same number of tickets, Tessier said.
Each Speed Sentry device costs about $4,000. Manchester's were purchased in 2007 by then-Lt. (now Capt.) Jon Hopkins of the Traffic Division.
Tessier said the units can flash like a speed board, if desired. "There's also a stealth mode," she said. "That's when the lights are turned off, and it just records data on number of cars and how fast they are going. When the speed is being shown, people have a tendency to slow down as they approach it. When it's off, you get a more accurate picture of how traffic is moving through the area."
"We'll get requests from the Traffic Division asking us to set one up," said Tessier. "Again, if there's already a stop sign there, it doesn't record who is going through the sign, just whether anyone is (not stopping) based on the speed of the vehicle. It's just collecting data."
"Because of the range they have, they can monitor speed of cars a good distance away," said Tessier. "If they are on a stop sign, we might not be watching how well the sign works. It might just have been the easiest spot to set one of them up."
"One area was South Mammoth Road," said Lt. Jim Flanagan of the Traffic Division. "We received complaints of people speeding along that area, set up the Sentry boxes, and when we looked at the numbers decided to allocate resources, when available, to that location for enforcement. We took a similar approach after data was collected along River Road."
Flanagan said he couldn't directly attribute speeding fines or traffic violations issued in an area to the fact that a Sentry box had been set up there prior to conducting enforcement activities.
"We don't assess or follow up with how many tickets were generated because sometimes just the presence of a cruiser and officer in an area is enough to get people to slow down," said Flanagan. "That's a success, without a fine being issued."
"We only have one right now, but we're looking to purchase two more," said Nashua police Capt. Bruce Hansen of that city's Traffic Division. "We set it up for three or four days at a time. If drivers can see their speed, your data can be skewed. Sometimes they speed up just to see how high they can get the numbers to go. One time, a kid stopped to throw a baseball near our speed board to see how fast he could throw it."
StealthStat information has been useful, Hansen said.
"West Hollis Street was one area that generated some staff time," said Hansen. "We looked at times in the day with the highest number of cars, then put an officer in place."
"They are used for counting cars and measuring speed only," said Concord Lt. Tim O'Malley. "They don't collect data on the drivers, the makes and models of the vehicles, or anything else."
"It utilizes two tubes that stretch across the road," said Londonderry police Lt. Tim Jones. "The tubes attach to a box that is usually chained to a telephone pole, and when cars pass over, it records the numbers and speed of passage. We can use the data to see if the area is in need of traffic enforcement. We generally only use it when we receive a complaint about speeding. We don't put the device out too often because of the wear and tear on the hoses."
New Hampshire isn't the only state using stealth radar boxes. Calls to police barracks in Burlington, Vt., Portland, Maine, and Framingham, Mass., confirmed they are deployed in those states, along with North Haven, Conn. Annual department reports posted online show they are also used in Ohio, North Carolina and Arizona.