Not long after new traffic signals went up at Stickney Avenue and Chrysler Drive in early 2001, Barb Jones got a phone call from an inquisitive Toledoan.

“She asked me, Why did you let Jeep put their security cameras on your poles? ” said Ms. Jones, the traffic signal engineer at the city transportation division.

But the cameras don t belong to DaimlerChrysler - they re part of the control system for the traffic lights. Instead of metal loops in the pavement, the Stickney-Chrysler intersection and a growing number of other corners in the region have video detectors to tell the light when to change.

Toledo hasn t put in enough video detectors to have a true measure of how beneficial they are, Ms. Jones said, but the technology offers the prospect of greater reliability and versatility and simpler maintenance.

“The biggest problem we have [with pavement loops] is utility repairs,” she said. “Every time you do a resurfacing, they get damaged.”

“The loops are always subject to freeze-thaw cycles and breaking,” agreed Jeff Ballmer, public service director in Sylvania, which has installed video detectors on Monroe Street at U.S. 23-Glasgow Road and at Main Street. “As they become a little more reasonably priced, I think we ll be putting a few more in.”

As well as the Stickney-Chrysler location, Toledo has installed video detectors at Byrne and Glanzman roads and on Glendale Avenue at the new Toledo Commons shopping center. Monroe Street, near Westfield Shoppingtown Franklin Park, is likely to be next when that stretch is resurfaced next year, Ms. Jones said.

Other locations with little white cameras perched on signal masts or light poles include a half-dozen recently renovated intersections on Airport Highway in Springfield Township and Buck Road at I-75 in Rossford.

When traffic signals are replaced on Central Avenue near I-475–U.S. 23 in Sylvania Township next year, video detection will be installed there, Ohio Department of Transportation officials said.

“We re going to see how it works,” Jason Yeray, ODOT s district traffic safety engineer in Bowling Green, said.

The cameras are connected to computers that scan the video readout to determine if vehicles are occupying any designated areas at a particular intersection. If so, the computer changes the traffic signal to allow those vehicles to proceed.

A typical four-way intersection costs about $22,000 for a camera installation, including control-cabinet hardware and labor, according to ODOT.

The cost of a pavement loop-detector system varies depending on the number of lanes and the number of loops per lane, but the loops cost $500 to $900 apiece, and wires and control equipment cost more, city and state officials said. At an intersection of two four-lane roads with single left-turn lanes, as many as two dozen detector loops could be in the pavement.

“On each approach, if you have five loops or more, you break even,” Mr. Yeray said.

But even at less complicated intersections where the installation cost for video may be higher than for in-pavement loops, the camera technology offers advantages beyond reduced maintenance expense.

Once a pavement loop is installed, for example, it can t be moved. A video camera can be re-aimed, and its lane-selection programming changed, from a remote computer.

“They re easy to adjust,” said Mike Stormer, ODOT s district planning engineer, who noted if traffic must be rerouted for a construction zone, or if a crash causes a short-term change in traffic patterns, changes can be made with a few keystrokes.

ODOT s control system has several layers of firewalls, Mr. Yeray added, so the risk of hacker tampering is slight, nor would there be much of a benefit of doing so.

The cameras resolution isn t good enough to record license plates or identify people in vehicles, but they can be used to take traffic counts and speed surveys, too.

“We re not going to build our way out of congestion,” Mr. Rutherford said. “But with fairly small measures like dynamic video detection, we can monitor and make immediate changes to help the flow of traffic.”

First Published December 29, 2003, 11:35 a.m.