What appears to be random and pointless words printed on a dozen street signs that dot the roadways in and around Bryan and College Station, Texas, may have implications for nighttime drivers across the country. The test signs are part of a three-year project to determine which signage materials provide the best reflectivity and are most readable. The project is being conducted by TTI for the Texas Department of Transportation (TxDOT) with cooperation from the City of College Station Traffic Engineering Office.
When the study is completed in February, about 100 volunteers will have been hooked up to an “eye-tracker” device that records their eye movements while they drive at night. When a sign is spotted, the driver reads the words aloud. With the help of an onboard Global Positioning System (GPS), the distance from the sign is noted by a TTI experimenter in the vehicle.
“This is one of the first studies in which we’ve had volunteers drive on open roads in our instrumented vehicle and eye tracker,” says TTI Senior Research Scientist Susan Chrysler. “Our primary concern, of course, is the safety of our volunteers while they are driving. So, we have another TTI employee riding in the front passenger seat to act as a safety observer.”
“This is the most sophisticated project for TxDOT I’ve been involved with,” says TTI Research Engineer Paul Carlson, who is a nationally recognized expert in the field of reflectivity and vision science. “This study will tell us lots of things that, up until now, we’ve only been able to speculate about.”
Researchers are taking numerous factors into consideration: the sign’s size, distance from the ground, level of reflectivity, when the sign becomes visible, and how long the illumination of the sign remains intact. After all the data are examined, TxDOT will develop guidelines for new roadway signs and will determine which materials perform the best in nighttime driving conditions.
The local study could also lead to roadway sign changes across the country. “The Federal Highway Administration is aware of our research,” says Carlson. “They want us to help develop national specifications based on the performance measures we’re studying.” Carlson says the ASTM International standards could mandate highway sign changes in the United States, so the research can potentially improve nighttime driving safety for drivers nationwide.