The Laughable Fiction of Travel-Demand Forecasts

The Virginia Department of Transportation and regional transportation planning organizations periodically make traffic forecasts for planning purposes. The idea makes sense in the abstract — estimating future volumes of traffic is needed to determine how much, and where, we should invest in new transportation infrastructure. Unfortunately, the process is flawed. Estimates have consistently overshot the mark in recent years, feeding the sense of transportation “crisis,” justifying the construction of uneconomical projects and feeding the clamor for higher taxes.