Over the last 15 years, we have learned that highways cause suburbanization and population growth. However, little is known about the resulting residential land use patterns. This paper aims to fill this gap by being the first to comprehensively analyze the effects of highways on sprawl. Using data from the Corine Land Cover project and the highway network for 579 European cities in 1990, 2000 and 2012, I find that a 10% increase in the stock of highways (km) causes a 1.1% growth in the residential land area, a 2% growth in the number of residential lots, and an increase of 25 p.p. in the share of undeveloped land surrounding residential land over this 20-year period. Overall, these results confirm that highways also cause residential sprawl by expanding cities with new, more fragmented and more isolated land developments.