PHILADELPHIA (CBS) — The Pennsylvania Turnpike is operating under a Weather Emergency on Wednesday.

Turnpike officials say speed limits are now reduced to 45 miles per hour from the Gateway Toll Barrier (Exit #2) east to the Delaware River Bridge Interchange (Exit #359) and the Northeastern Extension (I-476) from Mid-County (Exit #20) north to the Clarks Summit Interchange (Exit #131).

All travelers are urged to reduce their speeds and keep alert for changing travel conditions and emergency crews working on the roadway.

Drivers should stay alert for areas of snow with poor visibility, and icy roadway conditions.

Turnpike officials ask drivers to allow plenty of space when driving near plow trucks. Drivers should never attempt to pass a truck while it is plowing or spreading winter materials.

Tractor-trailers are restricted to travel in the right lane only in the mountain sections of the Turnpike between the New Stanton Interchange and the Breezewood Interchange.