Express bus lines can also work in a similar role: You end up taking a feeder route for 10-15 minutes that is barely faster than cycling[0], the switch to an express route where you have one or two stops and is equivalent in speed to driving. Obviously capacity is lower, but it's a lot cheaper to setup a bus route than rail route.

[0] Even in London where buses stop every few hundred meters they are faster than walking (unless there is a lot of traffic). How badly designed is GPs system?