In memoriam: Herbert Mohring, congestion pricing pioneer

Herbert Mohring, a transportationMohring economist who taught at the University of Minnesota from 1961–1994, died June 4. He is known for his pioneering work in the economics of public transportation and congestion pricing.

In the 1990s, Mohring served on a steering committee for the Minnesota Department of Transportation, and his thinking contributed to the opening of the I-394 MnPASS pay lane in 2005.

“Herb’s early work on congestion pricing in the 1960s helped lay the theoretical groundwork for congestion pricing,” says Lee Munnich, director of the State and Local Policy Program at the Humphrey School of Public Affairs.


Mohring is perhaps best known for identifying a significant positive feedback property of transit systems, now known as the Mohring Effect. In a 1972 paper, Mohring showed that increasing the frequency of transit service (and thereby reducing wait times) leads to an increase in demand as more potential riders choose transit; this growth in ridership drives further increases in service as the transit operator responds to the availability of more paying riders. The Mohring Effect influenced the development of transit requirements included in the Americans with Disabilities Act.

Mohring’s research also helped influence policymakers from Singapore to London. The fourth International Transport Economics Conference, held in Minneapolis in 2009, featured a special tribute in honor of Mohring. An international journal, Economics of Transportation, plans to devote an entire upcoming issue to honoring him.