A new 41-mile (65-kilometer) stretch of toll road between San Antonio and Austin is now open with an 85-mph (137-kph) speed limit, the highest posted speed limit in the United States.

State transportation officials hope that the speed limit will be an incentive for motorists to pay the roughly $12 toll to drive on the 90-mile (145-km) road. …

But some 18-wheel trucks, many of which are hauling items manufactured in Mexico to plants in the United States, may not be keen to take to the new road, according to Darrin Roth of the American Trucking Association. Many trucking companies prevent their vehicles from going faster than 70 mph or 75 mph, he said, and fuel consumption goes up exponentially as speeds increase – potentially cutting into company profits.