In case you haven't noticed yet, Houston is huge. Driving across the sprawling city can take over an hour, so be aware how far your destination is before setting out. To travel between Houston and Galveston, jump on I-45, the Gulf Freeway, which links the two cities. It's a pretty uneventful ride, especially during non-rush hours, but can get very congested on summer weekends. From Intercontinental Airport, the ride will be about two hours. From downtown Houston to Galveston, the trip's about an hour. Plan extra time into your schedule, since you never know what can happen on Texas freeways.