Problematic traffic-signal technology not in region

11/24/2003

It s sometimes good to be technologically challenged.

A device that allows emergency crews to override traffic signals in many cities has become so available and inexpensive that some authorities in Michigan and Ohio fear it could fall into the wrong hands.

But a survey by The Blade found drivers in Toledo and elsewhere in the region apparently need not worry about renegade motorists being able to preempt stoplights for their driving benefit. Local and state officials say the technology that would enable someone to use the device has not been installed on traffic signals around here.

“We made a conscious decision not to go with that,” said Barb Jones, signal engineer with the Toledo Division of Transportation. “Our system is very old. Some of our field equipment wouldn t be able to handle that. And we had some questions with the technology too.”

Instead, Toledo relies on fire, police, and rescue crews to slow down before passing through a red light and on motorists to give them the right-of-way when that is necessary.

At some 26,500 intersections in the nation s 78 largest metropolitan areas, stoplights are equipped with devices that can receive command signals from transmitters mounted inside emergency vehicles, the U.S. Department of Transportation determined last year.

Mobile infrared transmitters (MIRTs) have been available for about three decades. Slightly larger than radar detectors, they allow users to alter the normal stoplight cycle so the traffic signals switch to green lights and the roadway ahead is cleared.

Manufacturers say they are careful to restrict transmitter sales to legitimate users, which along with police, fire, and emergency medical responders could include highway maintenance vehicles, and even funeral directors seeking safe passage for lengthy funeral processions.

But after a $300 version of the transmitters became available on the market this year - a price less than half the previous prevailing cost - authorities in several states became concerned that they might be obtained by lead-footed drivers more interested in their own welfare than in public safety.

Several of the devices turned up for sale this month on the Internet auction service Ebay, which quickly barred the devices sale through its site and suspended a site user for selling one.

Mary Webster, assistant public service director for the city of Columbus, said potential misuse was among the reasons Ohio s capital city decided not to use MIRT systems after experimenting with them years ago. Cleveland took a pass on the technology too.

“We knew there were going to be gizmos out there that would do this,” Ms. Webster said. “Engineers can anticipate what other engineers are going to do.”

Toledo s Ms. Jones said early preemption devices used sound waves instead of infrared light, and city officials worried that stray noises might set them off. They also worried, she said, that two emergency vehicles approaching an intersection from conflicting directions may collide with each other or other traffic if each tried to use a device but only one got the expected green light.

Most importantly, however, was the cost to place transmitters in large numbers of emergency vehicles and retrofit stoplights with the receiving devices.

Paula Corlett, supervising engineer for the Michigan Department of Transportation s traffic signals unit, said MIRTs don t work very well with older electro-mechanical traffic signals. In many cases, she said, installing the new transmitter devices would require replacing signals with solid-state equipment, increasing the bill substantially.

Only a very few MDOT-maintained signals have MIRT receivers, Ms. Corlett said, and none is in the southeastern part of the state.

Most states have laws against interfering with traffic signals function, and several lawmakers, including U.S. Sen. Mike DeWine (R., Ohio) have proposed bills to outlaw unauthorized use of MIRTs and other signal-changing devices.

The primary makers of the devices, 3M Co. and Tomar Electronics, Inc., both offer encryption technology that can lock out unauthorized transmitters, but that adds about $2,500 to the systems cost.

The Associated Press contributed to this report.