If you've ever paid to drive in the express lane of Interstate 394, you have Herbert Mohring to thank.

Mohring helped inspire the MnPass lane -- as well as generations of students -- during his 33-year career as a professor of economics at the University of Minnesota. He died June 4 in Northfield at age 83.

Mohring, who looked the part of a pipe-smoking academic, was a pioneer in a field known as transportation economics. He was one of the first to come up with the idea of charging highway fees as a way to relieve traffic congestion -- a concept known as "congestion pricing."

His research, say colleagues, helped influence pol-icymakers from Singapore to London.

One of his theories, used to justify public subsidies of mass transit, has even been enshrined on Wikipedia as "The Mohring Effect."

"We tried to point it out to him," said his son, Stephen Mohring, an art professor at Carleton College in Northfield, noting that the Wikipedia entry is one of the first things to pop up when they Google their last name. But "he didn't quite get it."

Mohring was born in Buffalo, N.Y., in 1928, and earned a doctorate from the Massachusetts Institute of Technology. He landed at the University of Minnesota in 1961, as the Economics Department was starting to gain national prominence.

Mohring once described the life of a professor as "the world's most wonderful racket." Stephen Mohring said his father loved teaching, and thrived during an era when professors could "sit in front of the classroom and pontificate and smoke your pipe."

He was also known for his annual "Dammit, School's Starting" parties, which he hosted every August with his wife, Kalliope (Popie), who earned a doctorate after raising their three sons.

"I grew up thinking that that's what you did," Stephen Mohring said. "You get a graduate degree and then you [teach]."

His father had few hobbies, and often spent his free time in his study, writing books and academic articles.

Mohring knew some of his theories could be unpopular, said Lee Munnich, a senior fellow at the U's Humphrey School, who worked with Mohring.

Especially when they flew against the all-American notion that highways should be free. But Mohring thought that charging fees to use express lanes, especially at busy times, would make highway travel easier for everyone by reducing traffic in other lanes.

While his "congestion pricing" caught on in other parts of the globe, Mohring once predicted it wouldn't happen in the United States in his lifetime. But in the 1990s, he served on a steering committee for the Minnesota Department of Transportation, which eventually led to the opening of the I-394 pay lane in 2005. Last week, an international journal, Economics of Transportation, announced plans to devote an entire issue to honoring Mohring.

In addition to his son Stephen, Mohring -- who was widowed twice -- is survived by sons Andrew and Eric, both of Minneapolis, and five grandchildren. A family gathering in his honor is planned for June 30.

Maura Lerner • 612-673-7384