Galveston is 50 miles southeast of Houston on a barrier island connected to the mainland by two causeways. By car from Houston, take I-45 South all the way to the island — it's a straightforward drive that takes 45 minutes to an hour outside of traffic, but can take considerably longer on summer weekend afternoons when everyone is leaving at once. Park on the island; parking is available but limited in the Strand area on busy days.
There is no rail connection to Galveston. Houston Hobby Airport (HOU) is the closer of Houston's two airports and about 30 miles from Galveston; George Bush Intercontinental (IAH) is larger but farther north, adding significantly to the drive. Bus service from Houston's transit system (METRO) runs on weekdays but is not practical for tourist visits. Several private shuttle services connect the airports to Galveston hotels.
The Bolivar Ferry, operated free by the Texas Department of Transportation, runs from the eastern tip of the island to the Bolivar Peninsula — a scenic crossing of Galveston Bay that takes about 18 minutes and is worth doing as an excursion even if you have no business on the other side.