Houston to San Antonio connects the two largest metros in Texas, and the trip comes up constantly: business travel between the Energy Corridor and the South Texas Medical Center, families visiting across the I-10 corridor, students traveling to and from campuses in both cities, and flyers landing at Houston airports with plans waiting in San Antonio. This guide covers the route, realistic timing, airport pickup details, and how to book a door-to-door shuttle, grounded in corridor facts checked October 29, 2026.