It might not have been obvious at the time, but the massive fuel price spike last summer did have one hidden benefit: it eased congestion.
Take a look, for example, at this report from traffic information firm INRIX. I’ll let them summarize the numbers:
Overall, 96 of the 100 [metropolitan] markets, and all of the top 50 largest markets, had decreases in congestion during the first half of 2008…Across all roads and markets, roughly 26% of the peak hour [congestion] evaporated.
So when gas prices peaked, more than one-quarter of rush hour congestion simply disappeared. Similarly, rush hour travel times improved, with the “travel time index” (essentially, the time penalty for driving at rush hour) declining by about 7% in Seattle and 6% in Portland compared to the previous year.
I don’t mean to suggest that we all should be grateful for high gas prices. The price spike posed a real burden to lots of working families—a burden that was far greater than the limited and fairly concentrated benefits of congestion relief. I, for one, am not pining for the days when gas was over $4 per gallon.
Still, the numbers demonstrate two important points. First, relatively minor decreases in rush-hour travel can have big benefits for congestion: traffic volumes only have to go down a bit in order for traffic congestion to go down a lot. And second, people have significantly more ability to cut back on driving than we tend to think. Even at rush hour there are a lot of trips that aren’t vital, and that will “evaporate” when the costs of driving go up by as little as a dime per mile.