In accordance with 75 Pa.C.S. § 4530(b) (relating to portable emergency warning devices), when a bus is disabled or stopped for more than 10 minutes upon a highway, the driver shall display at least three portable warning devices. These portable warning devices shall be displayed as required by § 167.8 (relating to display).
67 Pa. Code § 171.150
The provisions of this §171.150 issued under the Vehicle Code, 75 Pa.C.S. §§ 4103, 4551-4553 and 6103.