75 Pa.C.S. § 3308: One-way roadways and rotary traffic islands.

(a) Establishment and marking.--The department and local authorities with respect to highways under their respective jurisdictions may designate any highway, roadway, part of a roadway or specific lanes upon which vehicular traffic shall proceed in one direction at all or such times as shall be indicated by official traffic-control devices.

(b) Driving on one-way roadway.--Upon a roadway designated for one-way traffic, a vehicle shall be driven only in the direction designated at all or such times as shall be indicated by official traffic-control devices.

(c) Driving around rotary traffic island.--A vehicle passing around a rotary traffic island shall be driven only to the right of the island.