Cortright: Everything that is wrong about highway travel forecasts in one chart

[OTRAN] Everything that is wrong about highway travel forecasts in one chart

The nation's highway planners are in complete denial about the declining demand for car travel in the US.  Nothing shows this better than a chart released by the State Sustainable Transportation Institute earlier this month.  Even though vehicle miles traveled have flat-lined for a decade, official DOT forecasts continue to predict un-relenting growth, real soon now.  The forecasts made in 1999 missed the US total travel by 22 percent--about three-quarters of a trillion miles.  And the latest forecasts predict the same growth rate as the old ones--starting next year.  And over-forecasting isn't a fluke--or the fault of the recession--SSTI reports that the DOT forecasts have over-estimated VMT growth 61 times in the past 61 years.

http://www.ssti.us/2013/12/new-travel-demand-projections-are-due-from-u-s-dot-will-they-be-accurate-this-time/

There's a technical name for this in forecasting:  the hockey stick--flat at the bottom left (past), and then rising sharply at the right (future).  The DOT projections are a row of hockey sticks, year-after-year.

This would be an amusing aside, if these numbers weren't being used to justify hundreds of millions (and billions) of dollars in largely un-needed investments in highways, including blunders like the Columbia River Crossing.  Where, oh where, are the reality-based highway planners?

Joe Cortright | Impresa