Mixing it up: Thomas Zehr builds long-lasting roads

The path to engineering wasn’t always straight for Thomas (Tom) Zehr, who has spent the past 22 years working as Illinois Department of Transportation’s hot-mix asphalt implementation engineer.

He credits his early interest in how things work to growing up on a farm in Ludlow, Illinois — a small town about 6 miles north of Rantoul.

From being the technical vice president of a satellite TV company to working as a carpenter in home repair and construction, Zehr attributes an assortment of jobs to his interest in engineering.

But there was one job in particular that caught his attention: working with motorcycles.

“In the early ’70s, I worked in production at a rapidly growing company in Rantoul. We manufactured motorcycle fairings,” Zehr said. “A lot of engineering practices were involved in the design and manufacturing process, and so I picked up on that.”

After taking career aptitude tests in his mid-30s, Zehr went on to receive his bachelor’s and master’s, both in civil engineering, from the University of Illinois at Urbana-Champaign.

While working on his master’s degree, Zehr explored hot-mix asphalt at the Advanced Transportation Research and Engineering Laboratory, which would later become Illinois Center for Transportation’s research laboratory.

“I was one of four students,” he said. “We were the first group of students to work in HMA at ATREL.”

After graduating, Zehr landed a job at IDOT’s Central Bureau of Materials, where he has served on the Technical Review Panel of more than 10 ICT projects.

Most notably is his effort with developing the Illinois Flexibility Index Test — a procedure used to identify hot-mix asphalts that tend to prematurely fail due to cracking.

Zehr served on the TRP for the project that developed I-FIT, “R27-128: Testing Protocols to Ensure Performance of High Asphalt Binder Replacement Mixes Using RAP and RAS.”

He recently furthered I-FIT efforts by serving as the TRP chair for project “R27-175: Development of Long-Term Aging Protocol for Implementation of the Illinois Flexibility Index Test (I-FIT),” which developed a procedure that accelerates the aging of I-FIT asphalt specimens in order to determine their long-term aging effects.

“The goal of these projects is to learn how to improve the materials and mixtures used to build and operate IDOT’s transportation network and make it more economical and, hopefully, safer,” Zehr said. “I think that, ultimately, what we learn can continue to give the public better bang for their buck.”

That’s exactly the kind of difference Zehr hopes to make in his service as TRP chair.

“The hope is that the traveling public should get longer-lasting pavements and, ultimately, better value for their tax dollars,” he said.