Perkiomen Valley Bus company. (thanks Steve!) It even touched bases with the Reading Railroad to facilitate customers to and from towns and the rail passenger service

https://www.flickr.com/photos/davidwilson1949/3428114062/

looks like this was an ambulance

The bus company was founded prior to 1925. In 1972, Clare M. and Christine Moyer of Pennsburg bought the Perkiomen Valley Bus Co.

 Perkiomen Tours now has about 70 full- and part-time workers, and its buses run tours and charters to hundreds of destinations each year.

April 1931

http://www.overdrive.fi/forum/threads/vanhoja-valokuvia-ameriikan-raitilta.267070/page-279#post-3064252
http://www.thereporteronline.com/article/RO/20020509/TMP01/305099984