UPDATE: I-79 has reopened as of 1:15 p.m.

Interstate 79 Northbound between exits 96 and 99 in Butler County is closed due to a jackknifed tractor trailer, according to the state Department of Transportation.

The crash was reported at about 10:45 a.m. on I-79 North near the 98.4 mile marker.

Traffic traveling northbound was redirected onto Route 488 via exit 96.

The estimated time to reopen is 1 p.m. but may change based on conditions, PennDOT said.

The speed limit on Interstate 79 was reduced earlier today to 45 mph, and all commercial vehicles are required to travel in the right lane between Exit 76 to the Route 19 exit in Cranberry Township, according to the state Department of Transportation.

PennDOT released the restrictions at about 9:25 a.m. as heavy snow continued to fall on Butler County.

Motorists are asked to use caution when traveling in winter weather, reduce speeds and be aware of changing weather conditions.

PennDOT officials say on packed snow, vehicle speed should be reduced by half, and on ice, vehicles should travel at a crawl.

More space should be allowed between vehicles proceeding down a road, street or highway in bad weather.

Brakes should be applied gently and operators should ease off if they begin to slide. Brakes can be reapplied after control of the vehicle is regained.

Cruise control should be avoided on slick roads, PennDOT said.

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