bcjack
03-05-2007, 08:42 PM
Courtesy the San Luis Tribune, March 5, 2007
San Luis Obispo: City, Caltrans seeing red over green lights
By Sally Connell
sconnell@thetribunenews.com (sconnell@thetribunenews.com)
http://www.sanluisobispo.com/images/sanluisobispo/sanluisobispo/16834/283397931236.jpg
Tribune photo by David Middlecamp
Traffic moves south into the city on Santa Rosa Street at the intersection with Foothill Boulevard. Caltrans has turned off infrared sensors used by emergency responders on selected lights on Santa Rosa Street, though they won't say which ones. Private citizens have been snarling traffic with illegal stoplight-changing devices.
Local drivers are illegally using infrared transmitters that change red stoplights to green at key intersections in the city, San Luis Obispo officials have found.
Such pre-emption technology has been available for nearly 30 years for use on fire trucks and ambulances. The devices transmit infrared signals to receivers at stoplights to change the red lights to green and speed emergency vehicles through intersections, improving response times.
People buying such "mobile infrared transmitters" illegally have used them across the nation and the state, but it was detected locally only recently.
Illegal use of the transmitters has disrupted the sequencing of traffic signals and caused congestion at intersections such as Marsh Street and Johnson Avenue, as well as along the Highway 1 portion of Santa Rosa Street through the north end of town.
The problem grew so acute at intersections along Santa Rosa that Caltrans turned off its infrared sensors on some stoplights it controls in the area. Now, fire trucks and ambulances can’t change red lights to green, slowing response times to emergencies.
Caltrans spokesman Jim Shivers said the agency made the choice because it believed the traffic hazard posed by constant use of illegal devices was more severe than disconnecting the receivers for emergency vehicles.
Shivers said the department won’t say where it had to disconnect the systems.
"We have important obligations for drivers, and one of them is the safe movement of traffic," he said. "We took the action so that drivers aren’t caught off guard by lights always changing suddenly."
"Caltrans appropriately decided to disconnect the systems," said San Luis Obispo Fire Chief John Callahan. "But then we lose the advantage in response times that we had before."
Response times are key to saving lives, he and other officials emphasize.
"The main thing is that instead of the normal flow of traffic during the day when there are no emergencies, you have people for their own selfish purpose pre-empting the system," Callahan said.
Callahan said traffic disruption is always a hazard, but there is also potential for real harm if a fire truck uses a preemption device at an intersection at the same time as an illegal user uses one. An accident could result.
To date, no local accident has been linked to the use of such infrared devices.
Making stoplights secure
The goal of local agencies now, under the stewardship of the San Luis Obispo Council of Governments, is to research how many stoplights in the county have pre-emption receivers and how expensive it would be to make them more secure.
Council planner James Worthley said his agency may apply as soon as April for a state grant to encrypt or encode county stoplights. Such encryption would make the signal pre-emption respond only to sanctioned transmitters on emergency vehicles.
The cost of dealing with individual stoplights would depend on the age of the system.
Worthley said the problem is that signal systems can’t recover if people are illegally using pre-emption systems over and over again.
"Cities like SLO have timed their signals so they work together in the best possible way," he said. "When emergency vehicles go through, it takes time for the signal to catch back up.
"If one signal gets hit multiple times within minutes of itself, then it takes a very long time for the signal to catch up and work properly."
Against the law
It is illegal in California to use devices that pre-empt signals. But the equipment remains for sale online at prices ranging from $270 to $600.
Fines for using an infrared transmitter illegally can reach $5,000 if there is no injury. If the illegal use results in injury or death, fines can reach $10,000 and the convicted can face jail or prison time, under California law.
President Bush signed similar legislation called the Safe Intersection Act forbidding the illegal use or sale of the transmitters nationwide in 2002.
But the problem can be so difficult to enforce that the California Highway Patrol has cited only six people for the offense since 2003 in the entire state.
"That’s about the smallest number I’ve ever gotten when I ran stats on citations," said CHP spokesman Tom Marshall, who is based in Sacramento.
He said enforcement would require a perfect confluence of an empty intersection, an available officer, a clear pre-emption, and the officer chasing down a suspect and finding the telltale device on the dashboard.
"It’s something where it’s important to have a law on the books, but it’s pretty hard to catch anybody for this," he said.
Mayor sees problem
The problem came to light locally around the time Mayor Dave Romero, who worked as a city public works director for 36 years, noticed a problem at Marsh and Johnson six to eight months ago.
"It was just out of whack," he said. Johnson, the busier street, was often getting the shorter green light. Romero complained to the Public Works Department, as did others.
Public Works Director Jay Walter said a signal maintenance operator in his department went out to inspect and initially found no problem, but then somebody used a preemption device while he was standing there.
"He was monitoring the cabinet, and it happened right in front of him," Walter said. "There was no fire truck on their way through, no emergency vehicle. He called and checked and no fire truck had gone through that intersection all day."
There was also no way to see who had pre-empted the light.
Further investigation showed it was happening elsewhere, Walter said.
Walter said the city may apply for a pilot grant for special equipment that would encode or encrypt four key signals in town for $15,000 to $20,000.
"We have 52 signals in town, and pretty much 90 percent of them do have the pre-emption technology," Walter said. "It could cost us maybe $500,000 to deal with."
Other communities
San Luis Obispo is the only city to report the problem, but other communities are on board and working with the Council of Governments to address the issue.
Paso Robles Public Works Director Doug Monn said the problem has not surfaced there, but he supports working to make the city’s signals secure.
Don Spagnolo, public works director for Arroyo Grande, said he hasn’t noticed the problem either.
But only three stoplights in his community don’t have the pre-emption systems for fire trucks and ambulances, and he is not sure why it wouldn’t happen in Arroyo Grande.
"You know we haven’t had it to my knowledge, but that’s not to say they aren’t out there doing it," Spagnolo said.
MORE INFORMATION
HOW IT WORKS
Infrared receivers are mounted on the stoplight or in the vicinity. Fire truck and ambulance drivers can hit an infrared transmitting device on their dashboard, sending out a signal to the stoplight from as far away as a quarter mile.
WHAT HAPPENS?
The sequencing on the light is pre-empted by the infrared transmitting device. Cross traffic will get a short yellow light allowing traffic to get through followed by red light, and the emergency vehicle should have a green light when it arrives.
AND ILLEGAL USERS?
Private parties using similar equipment do so illegally in California and most other states. But that doesn’t stop the equipment from being sold online. Enforcement is almost impossible, the California Highway Patrol reports.
WHAT’S THE TECHNICAL ISSUE?
After an emergency vehicle travels through an intersection, the signaling system can right itself in a cycle or two by shaving seconds from the different light times. If an intersection is hit by illegal devices repeatedly, the sequencing can’t recover easily.
WHAT’S THE SAFETY ISSUE?
Signal sequences are set for a reason to keep traffic moving. With overuse of these devices, lights can change quicker than drivers expect, causing accidents. Traffic congestion can force emergency responders to lose time in getting to fires and accidents.
AND A SOLUTION?
Current pre-emption systems are relatively open with a science similar to what is used for garage door openers. The goal is to secure the systems, allowing only encrypted or encoded use, with the presumption that they will be harder for illegal users to override.
— Sally Connell
San Luis Obispo: City, Caltrans seeing red over green lights
By Sally Connell
sconnell@thetribunenews.com (sconnell@thetribunenews.com)
http://www.sanluisobispo.com/images/sanluisobispo/sanluisobispo/16834/283397931236.jpg
Tribune photo by David Middlecamp
Traffic moves south into the city on Santa Rosa Street at the intersection with Foothill Boulevard. Caltrans has turned off infrared sensors used by emergency responders on selected lights on Santa Rosa Street, though they won't say which ones. Private citizens have been snarling traffic with illegal stoplight-changing devices.
Local drivers are illegally using infrared transmitters that change red stoplights to green at key intersections in the city, San Luis Obispo officials have found.
Such pre-emption technology has been available for nearly 30 years for use on fire trucks and ambulances. The devices transmit infrared signals to receivers at stoplights to change the red lights to green and speed emergency vehicles through intersections, improving response times.
People buying such "mobile infrared transmitters" illegally have used them across the nation and the state, but it was detected locally only recently.
Illegal use of the transmitters has disrupted the sequencing of traffic signals and caused congestion at intersections such as Marsh Street and Johnson Avenue, as well as along the Highway 1 portion of Santa Rosa Street through the north end of town.
The problem grew so acute at intersections along Santa Rosa that Caltrans turned off its infrared sensors on some stoplights it controls in the area. Now, fire trucks and ambulances can’t change red lights to green, slowing response times to emergencies.
Caltrans spokesman Jim Shivers said the agency made the choice because it believed the traffic hazard posed by constant use of illegal devices was more severe than disconnecting the receivers for emergency vehicles.
Shivers said the department won’t say where it had to disconnect the systems.
"We have important obligations for drivers, and one of them is the safe movement of traffic," he said. "We took the action so that drivers aren’t caught off guard by lights always changing suddenly."
"Caltrans appropriately decided to disconnect the systems," said San Luis Obispo Fire Chief John Callahan. "But then we lose the advantage in response times that we had before."
Response times are key to saving lives, he and other officials emphasize.
"The main thing is that instead of the normal flow of traffic during the day when there are no emergencies, you have people for their own selfish purpose pre-empting the system," Callahan said.
Callahan said traffic disruption is always a hazard, but there is also potential for real harm if a fire truck uses a preemption device at an intersection at the same time as an illegal user uses one. An accident could result.
To date, no local accident has been linked to the use of such infrared devices.
Making stoplights secure
The goal of local agencies now, under the stewardship of the San Luis Obispo Council of Governments, is to research how many stoplights in the county have pre-emption receivers and how expensive it would be to make them more secure.
Council planner James Worthley said his agency may apply as soon as April for a state grant to encrypt or encode county stoplights. Such encryption would make the signal pre-emption respond only to sanctioned transmitters on emergency vehicles.
The cost of dealing with individual stoplights would depend on the age of the system.
Worthley said the problem is that signal systems can’t recover if people are illegally using pre-emption systems over and over again.
"Cities like SLO have timed their signals so they work together in the best possible way," he said. "When emergency vehicles go through, it takes time for the signal to catch back up.
"If one signal gets hit multiple times within minutes of itself, then it takes a very long time for the signal to catch up and work properly."
Against the law
It is illegal in California to use devices that pre-empt signals. But the equipment remains for sale online at prices ranging from $270 to $600.
Fines for using an infrared transmitter illegally can reach $5,000 if there is no injury. If the illegal use results in injury or death, fines can reach $10,000 and the convicted can face jail or prison time, under California law.
President Bush signed similar legislation called the Safe Intersection Act forbidding the illegal use or sale of the transmitters nationwide in 2002.
But the problem can be so difficult to enforce that the California Highway Patrol has cited only six people for the offense since 2003 in the entire state.
"That’s about the smallest number I’ve ever gotten when I ran stats on citations," said CHP spokesman Tom Marshall, who is based in Sacramento.
He said enforcement would require a perfect confluence of an empty intersection, an available officer, a clear pre-emption, and the officer chasing down a suspect and finding the telltale device on the dashboard.
"It’s something where it’s important to have a law on the books, but it’s pretty hard to catch anybody for this," he said.
Mayor sees problem
The problem came to light locally around the time Mayor Dave Romero, who worked as a city public works director for 36 years, noticed a problem at Marsh and Johnson six to eight months ago.
"It was just out of whack," he said. Johnson, the busier street, was often getting the shorter green light. Romero complained to the Public Works Department, as did others.
Public Works Director Jay Walter said a signal maintenance operator in his department went out to inspect and initially found no problem, but then somebody used a preemption device while he was standing there.
"He was monitoring the cabinet, and it happened right in front of him," Walter said. "There was no fire truck on their way through, no emergency vehicle. He called and checked and no fire truck had gone through that intersection all day."
There was also no way to see who had pre-empted the light.
Further investigation showed it was happening elsewhere, Walter said.
Walter said the city may apply for a pilot grant for special equipment that would encode or encrypt four key signals in town for $15,000 to $20,000.
"We have 52 signals in town, and pretty much 90 percent of them do have the pre-emption technology," Walter said. "It could cost us maybe $500,000 to deal with."
Other communities
San Luis Obispo is the only city to report the problem, but other communities are on board and working with the Council of Governments to address the issue.
Paso Robles Public Works Director Doug Monn said the problem has not surfaced there, but he supports working to make the city’s signals secure.
Don Spagnolo, public works director for Arroyo Grande, said he hasn’t noticed the problem either.
But only three stoplights in his community don’t have the pre-emption systems for fire trucks and ambulances, and he is not sure why it wouldn’t happen in Arroyo Grande.
"You know we haven’t had it to my knowledge, but that’s not to say they aren’t out there doing it," Spagnolo said.
MORE INFORMATION
HOW IT WORKS
Infrared receivers are mounted on the stoplight or in the vicinity. Fire truck and ambulance drivers can hit an infrared transmitting device on their dashboard, sending out a signal to the stoplight from as far away as a quarter mile.
WHAT HAPPENS?
The sequencing on the light is pre-empted by the infrared transmitting device. Cross traffic will get a short yellow light allowing traffic to get through followed by red light, and the emergency vehicle should have a green light when it arrives.
AND ILLEGAL USERS?
Private parties using similar equipment do so illegally in California and most other states. But that doesn’t stop the equipment from being sold online. Enforcement is almost impossible, the California Highway Patrol reports.
WHAT’S THE TECHNICAL ISSUE?
After an emergency vehicle travels through an intersection, the signaling system can right itself in a cycle or two by shaving seconds from the different light times. If an intersection is hit by illegal devices repeatedly, the sequencing can’t recover easily.
WHAT’S THE SAFETY ISSUE?
Signal sequences are set for a reason to keep traffic moving. With overuse of these devices, lights can change quicker than drivers expect, causing accidents. Traffic congestion can force emergency responders to lose time in getting to fires and accidents.
AND A SOLUTION?
Current pre-emption systems are relatively open with a science similar to what is used for garage door openers. The goal is to secure the systems, allowing only encrypted or encoded use, with the presumption that they will be harder for illegal users to override.
— Sally Connell