The state Department of Transportation has lifted the speed limit and Tier 1 restrictions on Interstate 79 in Butler County.

The restrictions were put in place earlier today. A crash later shut down I-79 Northbound between exits 96 and 99 in Butler County. It was reopen shortly after 1 p.m.

A tractor trailer had jackknifed, 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.

PennDOT encourages motorists to "Know Before You Go" by checking conditions on Pennsylvania roadways by visiting www.511PA.com.

Also lifted is the speed limit restriction on Interstate 80 in Clarion and Jefferson Counties.

Users can also see plow truck routes/locations along a specific route in 511PA using the "Check My Route" tool. Plow truck locations will be indicated by dots along a roadway.

The time it takes for a plow truck to pass by the same point on the route depends on how heavy precipitation is and how much traffic is on the roadway, PennDOT said.

During a heavy and/or steady snowstorm, if snow is falling at one inch per hour and a truck route takes three hours to complete, three new inches of snow has fallen at the start of its route before the route is finished, PennDOT said. Crews continue to complete routes throughout the storm, but roadways will not be free of snow or ice during the storm.

PennDOT also reminds drivers to restock their emergency kits with items such as non-perishable food, water, first-aid supplies, warm clothes, a blanket, cell phone charger and a small snow shovel. Motorists should tailor their kits to any specific needs that they or their families have such as baby supplies, extra medication, and pet supplies.