Radar Signs Squelch Excessive Speed
Data Reveals Change In Drivers’ Behavior
After more than 500 days of deployment in downtown Randolph, a set of three radar-equipped speed monitoring signs has gathered nearly 430,000 data points on area drivers and their propensity to obey or exceed the posted speed limit.
According to data presented by Officer Matthew Chin to the Randolph Police Advisory Committee last Thursday, the speed monitoring signs show a significant decrease in excess speed for drivers traveling past eight locations including Elm Street, South Pleasant Street, and Forest Street.
First deployed last July and August, the signs gather data points on each passing vehicle in an effort to assist the Randolph Police Department in determining which streets may require further speed enforcement.
“They’ve been really well received,” said Ofc. Chin, “especially on roads we get complaints on… [at] a local level, they’ve really had an impact,” he said.
One key strategy to gathering quality data involved the simple flicking of a switch. By occasionally reconfiguring the signs’ settings to run in “data collection mode,” Chin deactivated the distinctive electronic display that flashed a bright yellow speed reading to passing motorists.
Appearing to lie dormant—and subsequently drawing a handful of resident complaints that they had stopped working—the signs con- tinued to quietly collect speed data on passing motorists. By comparing these data points with those generated when the display was illuminated, Ofc. Chin was able to determine how often—and to what degree—drivers moderated their speed.
“It’s logging your beginning speed and your end speed,” said Chin. “Based on that, we’re able to gauge changes in behavior,” he said.
Despite neighborhood reports of drivers traveling close to 60 or 70 miles per hour, signs positioned on Elm, Pleasant, and Forest Streets indicated that drivers seldom drove more than five or ten miles per hour above the posed speed limit.
When the signs’ digital display was activated, drivers tended to slow down dramatically, with many driving five miles per hour below the posted speed limit. A clear change of behavior.
In addition to radar, the signs are also equipped with cameras capable of snapping a quick photo of a speeding car as it whizzes past. Fortunately for hurried drivers, the cameras cannot be used to issue tickets of motorists traveling above the speed limit due their inability to accurately identify vehicle operators.
“As of the presentation last week,” said Chin in a follow-up email, “no enforcement action has been taken based upon the photos or the data collected by the signs,” he said, explaining that the RPD has no plans to use the signs for direct enforcement.
Described on their manufacturer’s website as “a kind of compassionate Big Brother that just wants to slow down drivers,” the signs were purchased through grants from the Governor’s Highway Safety Program and carry a maintenance cost of approximately $4,500 a year when paired with their accompanying data software.
For police committee member Tom Harty, this sticker price represents a net savings in terms of traffic enforcement and department expenses.
“The sign produces a result without manpower,” said Harty at the Thursday meeting. “That’s a cost savings. When the sign is on, people tend to slow down,” he said.
The signs cost an estimated 17 cents per hour to operate, compared to $56 an hour for an officer and a cruiser to monitor a given location.
“Ultimately, the purpose of the speed signs are to calm traffic,” said Chin. “[They’re meant] to be a data logger for speed analysis to better allocate resources for speed and traffic enforcement with the ultimate goal of making our roads safer.”
(This first appeared in the Herald of Randolph April 6, 2017)