Maintaining a consistency of highway signage is an important aspect of any agency that oversees highways.  Not only to protect the public behind the wheel, on foot, or a bike from calamities, but also to have a consistency in signage from one state to the next.  The Federal Highway Administration produces a publication entitled the Manual on Uniform Traffic Control Devices which lists every type of sign that can be installed on a highway or street in the United States.  This manual is the basis for states to build upon to by adding their own signs and the Keystone State is no different in this respect.

Unlike at the federal level, there is no single book that contains all of this information for the Commonwealth, but it is instead spread out over the Handbook of Approved Signs (Publication 236) PDFPavement Markings and Signing Standards (Publication 111) PDF, Temporary Traffic Control Guidelines (Publication 213) PDF, Traffic Engineering Manual (Publication 46) PDF, and Traffic Signal Design Handbook (Publication 149) PDF.

Regulatory Signs Warning Signs Construction and Maintenance Signs
Route and Auxiliary Markers Destination and Distance Signs Information Signs
School Signs Object Markers Traffic Signals
 
Previous Editions
Official Traffic Control Devices (1975)
1975
(104 MB PDF)
Handbook of Approved Signs (2006)
2006
(158 MB PDF)