Visibility research to be tested on 'smart road'
By Susan Trulove
Spectrum Volume 20 Issue 21 - February 19, 1998
Have you ever driven in a pouring rain or thick fog, uncertain where the edge of your lane or the road is? Have you ever barely missed a pedestrian on a dark night because you could not see him? Researchers in Virginia Tech's Center for Transportation Research and the Virginia Department of Transportation (VDOT) Research Council are working with several industries and agencies to solve the problem of night visibility for driving and pedestrian safety.
The center and VDOT have been awarded a $1.8-million grant from the Federal Highway Administration (FHWA) for enhanced night-visibility research, Congressman Rick Boucher announced Friday. Tom Dingus, Tech center director, is co-director of the $2.5-million project with Gary Allen, director of the Virginia Transportation Research Council.
Allen said, "Research in Sweden has shown that the use of fluorescent pavement markings and ultraviolet headlights, in conjunction with low-beam headlights, can double a driver's visibility distance during wet, night, road conditions."
Preliminary tests have shown that ultraviolet headlights, similar to "black lights" popular in the 60s and 70s, allow drivers to see up to 30-percent farther at night and increase the visibility of pedestrians. The research will seek to improve the safety of night driving by enhancing the visibility of road markings, signs, and pedestrians, Dingus said.
Ultraviolet (UV) technology "black light"--which is light in ranges the eye cannot see--reflecting off fluorescent materials is what makes a fish tank glow in a dimly lit restaurant. Phosphorus in detergents and even toothpaste are responsible for clothing and smiles that glow in dark discos.
Prototype headlights will contain both standard bulbs and the black lights. The special road markings will phosphoresce, reflecting a greater amount of light than painted surfaces. And it is believed that pedestrians will be easier to see because of the "disco-effect," the phosphorus left in clothing from detergent. Dingus said phosphorus also continues to glow for a time after UV light has been removed. "The material absorbs some of the energy and it takes awhile before it dissipates."
Researchers will test the prototype UV headlights and fluorescent-reactive pavement markings and lane delineators under conditions of variable lighting and weather. The Virginia Tech transportation center's "smart road" will serve as the controlled test site for the research. Then, up to 100 miles of additional Virginia roads will also be used in the testing.
The headlights are being provided by Ford Motor Company, and fluorescent-reactive paints and pavement markings are being provided by 3M Company, Day-Glo Color Corporation, and Carsonite International.
"This is the first example of how the `smart road' will bring research to Virginia Tech and the Center for Transportation Research," said Ray Pethtel, associate director of the center and university transportation fellow. "The award came to the Virginia because of the real-life laboratory the smart road offers, in addition to the expertise that exists at Virginia Tech and VDOT."
Virginia's Transportation Commissioner David R. Gehr said, "This project is one more step in VDOT's progress toward building `smart' highways, an overall plan to use the best technologies to make our transportation system increasingly safe and efficient for motorists."
The smart road, recently begun between Blacksburg and I-81 in Montgomery County, is a planned 5.7-mile limited-access highway with the first two miles designated for controlled testing and evaluation. This laboratory section will have variable lighting and the capability to create snow and rain. The first mile of road will be available to researchers this summer.
Once the UV technologies have been tested on the "smart road," the headlights and pavement markings will be tested in other Montgomery County locations, on Afton Mountain near Charlottesville, and on a section of highway in the high-traffic Northern Virginia/Washington, D.C. area. Volunteers' cars will be retrofitted with the prototype headlights. Use of the technology in real traffic conditions will help the researchers evaluate the safety benefits of the system.
The research team will address questions related to manufacturing, environmental health, and economic impact, as well as highway safety. Researchers will look at whether the materials are stable and environmentally sound, how long they will last, and where and under what conditions are fluorescent materials most useful.
"For example, most highway markers have UV protection coating to keep them from fading," Dingus said. However, it will probably be possible to filter out harmful UV from the B spectrum to protect markings and still admit useful UV light from the A spectrum to reflect from markings. "Wavelengths at the A level have largely proven to be safe," Dingus said.
If a UV system proves beneficial, researchers in the Virginia Tech center will help develop policies and procedures to deploy safer equipment and road markings, according to Aaron Schroeder, senior research associate with the center, who will facilitate the deployment phase. "We will work with automakers, public-safety interest groups, state departments of transportation, and federal agencies to come up with programs to deploy the technology in cars and on roadways," Schroeder said.
The research is expected to take 42 months.