The country's first automated highway fog-alert system is coming to Utah in a pilot project that will appear on the I-215 site of a 68-car pileup that injured more than a dozen people in December 1988.
The Department of Transportation has contracted with Clearfield-based Rockwell International to install four fog sensors near the spot where the interstate crosses the Jordan River on the west edge of Murray. The work marks the first phase of the project, which will be finished next summer when UDOT ties the sensors into electronic signs that will alert motorists to the presence of murky conditions and advise them of what speed to drive.Sara Riley Colosimo, UDOT's research project manager, said fog-alert systems aren't uncommon but that this is the first time a completely automated one has been tried.
UDOT operates fog-warning signs on the end of I-215 north at its intersection with Redwood Road in North Salt Lake, where five people died in a 66-car accident in January 1991, but those are triggered manually - and inconsistently, because UDOT doesn't monitor the area around the clock.
"The fog often rolls in at four in the morning, and you have to get somebody up to go look at it," said Colosimo. "We have a credibility problem there."
She said the southern I-215 site was chosen over the northern one because fog is a more frequent problem at the Murray section of the belt route, which circles Salt Lake City.
Fog frequency was compiled using state police accident reports.
Dubbed Project ADVISE - for Adverse Visibility Informational System Evaluation - the fog-alert system will rely on infrared sensors that have been used since the 1970s in similar applications at airports. UDOT will include in the project traffic-measuring devices that will chart the speed of motorists.
"Part of this is a look at traffic behavior in fog," said Colosimo. "The theory is that accidents occur because of large variations in speed . . . some people will just keep going at 55 mph through fog; others hit the brakes. We want to see if the signs will have any effect."
The project is funded mostly by a $425,000 federal highway grant, with UDOT kicking in about $75,000. Only two states - Utah and Georgia - were picked for the pilot program.
In choosing a site for the system UDOT considered, in addition to the I-215 locales, I-15 where it rounds the Point of the Mountain. Though visibility is sometimes a problem in that area, it is created more often by high winds than fog, a condition for which the technology is not as well-suited.