Reasons for Recent Large Increases in Commute Durations
Report no. MnDOT 2007-02
Commute durations in Minnesota increased by about two and a half minutes on average during the 1990s. Given earlier evidence suggesting that commute times remain fairly stable over time, this was a surprisingly large increase. The research described in this report was undertaken to try to identify reasons for this increase, and, specifically, for why it happened when and where it did.
Growth in commute durations does not appear to have been significantly driven by land use or economic factors. Commutes grew slower in the Twin Cities and other urban counties than in the rest of the state, despite congestion and land use changes in these areas. And overall there was little correlation between economic factors and the rate commute growth, especially outside the Twin Cities area.
Some of the increase seems to be due to a change in methodology in the 2000 census. Adjusting for this, the overall commute time increase in the 1990s (11%) was slightly larger than in the 1980s (7%) because in the 1980s travel speeds statewide increased slightly, offsetting longer distances to some degree. Because speeds statewide remained constant in the 1990s, all the increase in distance was reflected in longer travel times.