This study explores the extent to which changes in transport infrastructure counterbalance pre-existing geographical friction and foster innovation collaboration, using the Chinese high-speed rail (HSR) construction as a quasi-natural experiment. Using a comprehensive dataset of city-pair co-patents from 2005 to 2018, we show that HSR connections significantly increase intercity co-patents, patent quality and collaborative partnerships, and such effects are strongest for city-pairs within 250 km and decrease for longer distances. Moreover, the HSR effect is...