The WRTA has this weird thing where they have routes to serve towns that are a bit away from Worcester. It's a good thing, but odd because they don't serve other places that are a bit closer.
One of those towns is Southbridge, which is served by the 29.
The bus runs from Union Station in downtown Worcester to Southbridge, via Auburn and Charlton. It runs on US Route 20, a high-speed road that the WRTA will only let passengers board and get off at one location in each direction along this stretch of the route. Also it's two different places they stop at.
The bus runs every two hours Monday through Saturday, and starts at about 5:30 am on weekdays and at about 8:00 am on Saturdays. The route has all-day service running until about 8 pm.
For Southbridge, it seems to do the job. It stops right in the center of town and gets passengers to Worcester in just under an hour.
But why only Southbridge? The bus runs right through Charlton and doesn't serve much there. Both Oxford and Auburn are served by other WRTA routes and are along the 29. What made the WRTA create a whole route to go all the way to Southbridge? I don't know.