A recent study by the Texas A&M Transportation Institute is only the latest to name Washington, D.C. as the worst traffic city in the nation. For those who live and commute in the metropolitan area it is old and tired news full of arguments over road expansion, carpool lanes, the unreliability of the Metro, expansion of the Metro, transportation funding etc.
The study looked at something called the Planning Time Index (PTI) of travel in major U.S. cities. PTI is a measurement of predictability of travel time–for instance how early one would have to leave in order to arrive on time for an important event such as a job interview. D.C. topped the list with estimates of it taking more than three hours for a trip that should take thirty minutes without traffic.
