From the 1911 passage of the
Sproul Road Bill to the 1987 adoption of the
Location Referencing System, all
state highway
A state highway, state road, or state route (and the equivalent provincial highway, provincial road, or provincial route) is usually a road that is either ''numbered'' or ''maintained'' by a sub-national state or province. A road numbered by a ...
s in the
U.S. state
In the United States, a state is a constituent political entity, of which there are 50. Bound together in a political union, each state holds governmental jurisdiction over a separate and defined geographic territory where it shares its sover ...
of
Pennsylvania
Pennsylvania (; ( Pennsylvania Dutch: )), officially the Commonwealth of Pennsylvania, is a state spanning the Mid-Atlantic, Northeastern, Appalachian, and Great Lakes regions of the United States. It borders Delaware to its southeast, ...
were defined as
legislative route
In the United States, a legislative route (LR) or legislative highway is a highway defined by laws passed in a state legislature. The numbering of such highways may or may not correspond to the numbers familiar to the public as part of the state, ...
s, while some were also posted as ''Traffic Routes''. Major routes were assigned three- or four-digit numbers, while minor routes were given five-digit numbers in which the first two digits represented the
county
A county is a geographic region of a country used for administrative or other purposesChambers Dictionary, L. Brookes (ed.), 2005, Chambers Harrap Publishers Ltd, Edinburgh in certain modern nations. The term is derived from the Old French ...
, in alphabetical order from 1 (Adams) to 66 (York). (
Philadelphia County
Philadelphia County is a county in the Commonwealth of Pennsylvania. It is the most populous county in Pennsylvania. As of the 2020 census, Philadelphia County had a population of 1,603,797. The county is the second smallest county in Pennsyl ...
was initially skipped, but later assigned the number 67.)
State-aid projects, which were carried out even before 1911, received their own permanent numbers - State Aid Application X (SAA X or A-X). Many short routes or realignments were defined as spur or parallel routes to another route.
Often a route remained on its old alignment, while the signed Traffic Route was moved to a newer bypass with a different number.
1-999
1000-9999
See also
*
*
References
Historic County Maps*
{{reflist, 2
Legislative