Apparently, high gas prices and a slowing economy really did ease congestion last year:  a national traffic scorecard released by transportation analysis firm INRIX found that traffic backups eased in each of the top 100 metro areas in the US. 

portland congestion mapAnd it wasn’t a minor dip, either.  Peak-hour congestion fell by 29 percent nationwide.  Fifiteen cities experienced net congestion declines of 50 percent or more.  Northwest cities fared about average:  congestion declined by 28 percent in Seattle, and 34 percent in Portland. (The INRIX methodology is here, if you’re interested.  There are obviously a lot of ways of measuring congestion, but they do a good job explaining what their numbers mean.) 

It should come as little surprise, perhaps, that congestion declined in the US.  Driving was down, and transit ridership was hitting new highs.  Still, it’s good to have the intuitions confirmed with solid data.