South Padre Island to Rio Grande Valley International Airport, Harlingen, on Texas Highway 100 and FM 510 and 106 (33 miles)
This narrow two-lane shortcut from the beach to the airport is one way to avoid the congestion and speed traps on U.S. 77. It slices through parts of the Laguna Atascosa National Wildlife Refuge, which is particularly thick with activity around sunrise and sunset, and passes right by the Texas Air Museum in Rio Hondo.
Van Horn to El Paso on Texas Highway 54 and U.S. 62 (156 miles) This alternative to Interstate 10 adds 35 miles to an already long drive, but try it at least once. The first half runs below the eastern face of the Sierra Diablo and ends at Guadalupe Pass at the base of El Capitan, the landmark peak of the Guadalupe Mountains. U.S. 62 is a long cruise through high desert, with great over-the-shoulder views of the Guads. The road gets a little twisty entering the Hueco Mountains; otherwise it's a straight shot through barren wilderness and the occasional junkyard to El Paso.
Belton to Burleson on Texas Highways 317, 6, and 174 (124 miles) This end run around deadly dull Interstate 35 could be dubbed the Presidential Highway, since it puts you near the Western White House at Crawford. Between Clifton and Meridian, the route follows the Bosque River Valley, a scenic lost chunk of the Hill Country, then crosses the Brazos on the way to Cleburne, one of the most charming old towns in north-central Texas, before rejoining I-35.
Bastrop to Smithville on Park Road 1 (17 miles) There's nothing wrong with the parallel stretch of Texas Highway 71, the western half of the popular Austin-to-Houston route. But I like to detour onto this lightly traveled park road connecting Bastrop and Buescher state parks to see the sunlight flicker like a strobe through the Lost Pines, the densest forest this side of the Big Thicket.
Northeast El Paso to northwest El Paso on Texas Highway 375 (13 miles)
This route around downtown El Paso linking U.S. 54 with I-10 packs a lot into a little mileage: the boundary of the artillery range attached to Fort Bliss on the east slope, a network of hiking trails just off the road near the mile-high summit at Smuggler's Gap, and a knockout westward view of the verdant Rio Grande Valley.