ROBSTOWN, Tex. — Leon Little’s farm here near Corpus Christi would not be seized for Texas’s proposed $184-billion-plus superhighway project for 5 or 10 years, if ever. But Mr. Little was alarmed enough to show up Wednesday night with hundreds of his South Texas coastal neighbors to do what the Texas Department of Transportation has been urging: “Go ahead, don’t hold back.†Don’t worry. Texans have gotten the message, swamping hearings and town meetings across the state to grill and often excoriate agency officials about a colossal traffic makeover known as the Trans-Texas Corridor, a public-private partnership unrivaled in the...