Beginning in 1914, intrastate bus service was regulated by the Pennsylvania Public Service Commission, later the Pennsylvania Public Utility Commission. Information could not be located, regarding the issuance of Certificates of Convenience and Necessity for bus service. But the April 1922 issue of the publication "Bus Transportation" included a table listing the bus routes in existence in Pennsylvania.
Not listed are city bus routes, along with bus routes of a suburban nature operating strictly within one county.
This information does not include the actual bus companies operating the routes. And it was not possible, to establish how these companies became part of the Greyhound or other larger bus companies.
Allentown-Pennsburg Altoona-Patton Beaver Meadows-Hazleton Bellefonte-Lock Haven Bellefonte-State College Berwick-Beach Haven Blairsville-Derry Boalsburg-Lewistown Bradford-Smethport Brownsville-Washington Butler-Culmerville Butler-Slippery Rock Carbondale-Honesdale Chambersburg-Harrisburg Chambersburg-McConnellsburg Media-Kennett Square Danville-Sunbury Erie-Union City Franklin-Polk Franklin-Reno Gettysburg-Harrisburg Gettysburg-Emmitsburg MD Gettysburg-Littlestown Gettysburg-Hanover Harrisburg-Liverpool Harrisburg-Mount Holly Springs Hawley-Honesdale Hazleton-Mahanoy City Hazleton-Sheppton Hazleton-Tamaqua Hendersonville-Bridgeville Hendersonville-Canonsburg Hollidaysburg-Altoona Hollidaysburg-Roaring Spring Hollidaysburg-Sproul Houston-Canonsburg Houston-Westland-Hickory Jerome-Johnstown Johnstown-Somerset Kane-Mount Jewett Lehighton-Stroudsburg Littlestown-Westminster MD Lewistown-Bellefonte Lewistown-Millerstown Matamoras-Bushkill McConnellsburg-Everett Mercersburg-Hagerstown MD Mifflintown-Burnham Millersburg-Lykens Milroy-Burnham Pottstown-Amityville Reading-Hamburg Reading-Pottstown Selinsgrove-Hoffer Selinsgrove-Mifflintown Somerset-Meyersdale Somerset-Ligonier Tyrone-State College Towanda-Lopez Towanda-Mansfield Towanda-Sayre Uniontown-Farmington Uniontown-Smithfield Wellsboro-Mansfield Warren-Youngsville West Chester-Wilmington DE Williamsport-Muncy Williamsport-Trout Run York-Gettysburg