Three ISU students are sacrificing sleep to make bridges safer for motorists this winter.

Tina Greenfield, Brian Tentinger and Jose Alamo measure the frost levels of three local bridges every morning at 5. There are only two instances when the students get a reprieve — when there is already snow or ice on the road, or if the temperature is too high for there to be frost.

The three test the State Avenue, South Dakota Avenue and the County Line bridges, which are all over Highway 30. They were selected because of their proximity to each other — they are each separated by one mile.

Frost develops when two critical events occur: the bridge temperature is below freezing or the dew point temperature is above the bridge temperature.

Greenfield, graduate student in geological and atmospheric sciences, said she, Tentinger and Alamo take turns testing the levels every morning. She said on her morning to test, she gets up and gathers her flashlight, an infrared thermometer and a reflective vest the Department of Transportation requires each of the students to wear while testing. And then she’s off.

“I get out of my car and go onto the bridge, then I take out my thermometer and test the levels. If there is no frost, I can go back to bed. If there is, I check up on it again every half hour until the frost goes away. This could take until about 9 a.m.,” Greenfield said.

Greenfield said it is difficult to measure the exact depth of the frost, so they only observe whether frost is present. They use only their flashlights, thermometers and eyes to record the results.

Any level of frost is a dangerous, she said, because the Department of Transportation has no way to tell how thick the frost is.

Greenfield said some bridges are more dangerous than others.

“County Line Bridge is always the slickest. If there is just a little bit of frost, it is much slicker than State Avenue Bridge, which is never as slick as the other bridges — no matter how much frost is present,”

she said.

Greenfield began this project as an undergraduate senior. She was able to receive a two-year graduate assistant grant from the Department of Transportation to continue her research on this project.

Greenfield said she plans to complete her research on the bridges by next May and she is not sure whether or not the group will continue to observe the frost on the bridges next year.

Alamo, junior in meteorology, saw a flier about the project and contacted Greenfield immediately. Alamo grew up in Guaynabo, Puerto Rico, and said he was interested in learning about the chilly climate.

“One of the reasons I came here was to study the cold weather because it is something my family and I had never been exposed to,” he said. “It interests me because it is something very different.”

Alamo also said he was interested in helping the Department of Transportation and contributing to Greenfield’s research.

Gene Takle, professor of geological and atmospheric studies and agronomy, is the principal investigator of the project and the faculty member who oversees the research. He said it is crucial to monitor the frost levels of bridges.

“Frost presents a hazard to motorists, especially when roadways are clear. A motorist will come to a bridge and not realize how slick it may be. This presents a dangerous problem,” he said.

Takle said there is not a standard procedure to forecast frost, which is what he hopes to develop. He said he also hopes monitoring frost levels will prevent motor vehicle accidents.

Greenfield agrees it is important to monitor frost levels on bridges.

“Our goal is to find a better way for prediction of frost,” Greenfield said.

“The Department of Transportation spends a lot of money trying to do this, and we would like to find a way to know ahead of time. Our test is the only way to get a reliable set of observations, and we use our observations for our research.”