YOUNGSTOWN - Drivers may want to get an early start on their Friday morning commute as the Valley is under a winter weather advisory until 4 am Saturday.

With additional snow accumulations of 2 to 4 inches expected in Trumbull and Mahoning Counties, several schools are closed and some communities have parking bans.

The Ohio Department of Transportation issued a statement saying that travel is expected to be challenging through Friday for much of the state. Heavier lake-effect snow is expected to hit portions of northeast Ohio later Friday and Saturday.

As of 5 a.m., ODOT was using 25 trucks in Trumbull County; 20 in Mahoning County; and 17 in Columbiana County.

The Youngstown Street Department had 15 trucks plowing and salting roads.

Over in Mercer County, Pennsylvania, PennDOT was running 27 trucks.

The following vehicle restrictions are in effect in Pennsylvania:

Interstate 79:
· Tier 2 vehicle restriction from the I-80 interchange in Mercer County to the West Virginia state border.
· 45 mph speed reduction with commercial vehicles not covered by the Tier 2 restriction allowed in the right lane only from the I-80 interchange in Mercer County to the I-376 interchange in Allegheny County.

Interstate 80:
· Tier 1 vehicle restriction from the Ohio state border to the New Jersey state border.
· 45 mph speed reduction with commercial vehicles not covered by the Tier 1 restriction allowed in the right lane only from Exit 42 (Route 38, Emlenton) in Venango County to Exit 161 (Route 220, Bellefonte) in Centre County.

Interstate 376:
· Tier 2 vehicle restriction for the entire length of the highway from Mercer County to Allegheny County.
· 45 mph speed reduction with commercial vehicles not covered by the Tier 2 restriction allowed in the right lane only from Exit 5 (Route 208, New Wilmington/Pulaski) in Lawrence County to the ending point in Allegheny County.

Check www.511PA.com for additinal information on restrictions throughout in place throughout the state.
Restrictions are communicated via variable message boards, the 511PA traveler information website at www.511PA.com and smartphone apps. Motorists can also sign up for alerts on the website.
Under Tier 1 restrictions, the following vehicles are not permitted on affected roadways:
Tractors without trailers.
Tractors towing unloaded or lightly loaded enclosed trailers, open trailers or tank trailers.
Tractors towing unloaded or lightly loaded tandem trailers.
Enclosed unloaded or lightly loaded cargo delivery trucks/box trucks that meet the definition of a CMV.
Passenger vehicles (cars, SUV’s, pickup trucks, etc.) towing trailers.
Recreational vehicles/motorhomes.
School buses, commercial buses and motor coaches.
Motorcycles.

On roadways with Tier 2 restrictions in place, vehicles prohibited under Tier 1 are not permitted, as well as:
Commercial vehicles towing loaded tandem trailers without chains or Alternate Traction Devices (ATDs).
· All loaded or unloaded school buses, commercial buses, and motor coaches regardless of the availability of chains or ATDs.