Texas → Texas · Interstate 45 (Gulf Freeway)
On heavy-rain or dense-fog days the Houston, Texas, to San Antonio, Texas, leg routinely demands well more than the 3h 25m estimated: Interstate 45 (Gulf Freeway) carries known hydroplaning hot spots and reduced-visibility corridors that justify dropping to 35 mph through a few short stretches. The outbound run covers 359 km (223 miles) over varied topography between Houston (the fourth-largest US city and energy capital of the world) and San Antonio (the home of the Alamo and seventh-largest US city), demanding sharper attention on mountain descents and shoulder-less curves. Before pulling out, check brake-pad wear, tire tread depth, and washer-fluid level in the reservoir. Fuel spend holds near $29.99 for the 32.6 liters (8.6 gallons) consumed. Even in adverse conditions, the flat tariff of $0.43/km guarantees the standard outbound payout of $154.37 — log any incidental costs (extra toll, mandatory meal, emergency lodging) in a separate field on the Clara receipt.