The speed limit will increase to 70 mph on sections of three highways later this month.

The Wyoming Department of Transportation says in a press release that the increased speed limits will be posted on much of US 85 east of the I-25 interchange north of Cheyenne to Newcastle, on WYO 130 from I-80 south to Saratoga, and WYO 120 from roughly 18 miles north of Cody to the Montana border.

The department will notify the public when the sign change is complete and the new limit goes into effect.  WYDOT expects the change to take about one day under favorable weather conditions.

The state Legislature approved the higher speed limit for two-lane rural highways last year, and a study was conducted to identify segments of highway that could safely handle 70 mph traffic.

“That study for these three highways found it safe and reasonable to increase the limit to 70 mph on these sections,” said WYDOT Chief Engineer Gregg Fredrick.

The speed limits on stretches of roadway next to communities will remain the same.

The study evaluated factors including terrain, crash histories, and traffic volumes.  It found that travel speeds on the three highways were already in the 70 mph range.

The department does not expect the increased speed limit to result in significantly higher speeds, and the Wyoming Highway Patrol will work to prevent any such increases.

“We will keep an eye on it,” said department spokesman Dave Kingham.  “If any problems arise, we’ll reconsider the increase.”

The department is currently studying about 1,314 additional miles of highway to determine if speed limits could be safely increased to 70 mph.