At 80 miles per hour, Texas now lays claim to the highest speed limit in the country.
Signs indicating the change from 75 miles-per-hour to 80 miles-per-hour began going up along 521 miles of interstates in ten sparsely populated counties in West Texas just days after state transportation officials approved the increase late last month.
The new speed limit is on an 89-mile stretch of Interstate-20 between Monahans and the Interstate 10 interchange at the edge of the Jeff Davis Mountains.
It's also 80 for the 432 miles between Kerrville and El Paso on I-10.
The stretches are mostly flat and straight and get far less traffic than other parts of Texas.
Texas transportation officials say fatalities dropped when the speed limit was raised to 75 miles per hour on some roads.
That mirrored similar data when the national 55 miles per hour limit was boosted. Thirteen states have speed limits of 75 or higher on some roads.
Higher speeds could come at a price -- the Department of Energy estimates that every five miles per hour over 60 costs drivers an extra 20 cents per gallon.