A chunk of the Pennsylvania Turnpike in the central and eastern region of the state is switching this week to a 70-mph limit.
Legislation passed last year allowed interstates, including the Turnpike, to increase the maximum speed to 70 miles an hour, up from 65 miles an hour.
But transportation agencies have the final say about enacting higher speed limits.
PennDOT Secretary Barry Schoch said the lawmakers’ control over highway speeds is a holdover from the 1970s U.S. oil crisis.
“They rolled the speed limit, maximum speed on the interstates, back to 55 nationally. So it became legislated then,” he explained. “And then the states sort of mirrored that legislation with their own maximum speeds. And if you didn’t do it, if you didn’t enact the legislation to roll it back, you lost federal funding.
“So I think that’s when it originated. So since then, it’s always stayed in the hands of the legislature in terms of maximum speed,” Schoch continued.
Portions of Interstates 80 and 380 will also have the 70-mph limit posted next month.
Interstates in Pennsylvania were designed to handle traffic going 70 mph, Schoch said.
“We’re basically back to where we started, that the cap is back where we designed it to start with. To raise it any higher, for example, would be fruitless,’ he said. “We didn’t design any of this system to be any higher than 70 miles an hour.”
The changes, which take effect this week on the Turnpike and Aug. 11 on the interstates, could be rescinded if they appear to compromise safety over the next year.