Time on the Road and the Price of Gasoline : Evidence from ATUS and NHTS

What happens when motor fuel prices rise? In the US, the National Household Travel Survey (NHTS) collects information about car ownership and use, and travel during a typical day, for over 100,000 households. It is conducted only once every 8 years, and does not include a longitudinal component, making it difficult to observe drivers’ adjustments to changing gasoline prices. We experiment with combining the 2017 NHTS with eight waves of the American Time Use Survey (ATUS), which tracks trips, time spent traveling, and other characteristics of each trip. We find that the two datasets document remarkably similar behaviors—whether we use the eight waves of the ATUS or limit the comparison to the period when the two surveys overlap (April 2016 to April 2017). They also document similar responsiveness to prices—at least for the decision to take a car or a public transit trip. By contrast, minutes on the road and miles in the NHTS appear to be strongly responsive to gasoline prices, whereas minutes on the road from the ATUS are unrelated to fuel prices, despite the much greater price variation therein. This has important consequences when calculating the emissions reductions that can be expected when the price of gasoline rises. The results are robust to extensive checks and efforts to reduce measurement error in gasoline prices