The protesters had blocked a downtown intersection near Gov. Tom Corbett's local office. Charges against those arrested Friday include disorderly conduct and obstructing traffic.
The demonstration followed a march and rally protesting fare increases, elimination of bus routes and possible layoffs.
In April, the Port Authority of Allegheny County approved the largest service cuts in its history due to a projected $64 million budget deficit.
The transit agency serves Pittsburgh and its suburbs.