We estimate models of scrappage rates and survival probabilities as a function of vehicle age for U.S. light-duty vehicles. We use counts of vehicles in operation by vehicle type and model year for calendar years 2002-2020, which allows us to estimate scrappage functions for years 2003-2020. We estimate models for three vehicle types: passenger cars, SUVs and vans, and pickup trucks. We found that modified logistic functions fit the data well for each vehicle type. Results of estimation via nonlinear least squares indicate that life expectancies for all three vehicle types increased over the study period by 2-3 years for passenger cars, 3-4 years for SUVs and Vans, and 5-6 years for pickup trucks. By 2020, median expected lifetimes ranged from about 17 years for passenger cars, and 20 years for SUVs and vans, to about 25 years for pickup trucks. A review of historical trends in the life expectancies of U.S. light-duty vehicles indicates they have been increasing by 0.5% to 1% per year for over 50 years. We develop a method for projecting future survival functions by extrapolating from our estimated survival functions. Our findings have significant implications for policies geared toward reducing fuel use and greenhouse gas emissions.
