Pennsylvania Code
Title 67 - TRANSPORTATION
Part I - Department of Transportation
Subpart A - Vehicle Code Provisions
Article VII - Vehicle Characteristics
Chapter 171 - SCHOOL BUSES AND SCHOOL VEHICLES
Subchapter F - MASS TRANSIT PUPIL TRANSPORTATION BUS STANDARDS
Section 171.135 - Mirrors

A mass transit pupil transportation bus shall be equipped with a system of mirrors that gives the seated driver a view of the roadway to each side of the bus and the area immediately in front of the front bumper, so that when a rod 30 inches long is placed upright on the ground at a point along a traverse line 1 foot forward of the forwardmost point of the bus and extending the width of the bus, at least 7-1/2 inches of the length of the rod shall be visible to the driver either by direct view or by means of an indirect visibility system.