I had this idea sometime back while I was commuting to work by bus. I used to commute by bus daily but then broke the trend and started driving. Driving to work for me is substantially faster (20 minutes vs. 55 minutes) though the drawback is that, well, I need to drive instead of leisure reading which I enjoy doing on the bus.
Recently, one day I had to commute by bus again, and it got me comparing the two modes of transport. The bus takes a faster route to work than I do by car (because it can use the carpool lane on a highway which is very crowded otherwise). The main reason why the bus takes so much time is because it stops very frequently. The many stops add up fast. The same logic holds for trains as well.
OTOH, we kind of already know how to get around it. We have express routes. These are routes which have very few stops. The problem is that there are few of them.
I think there may be a way to solve this problem. The crux of the idea is to classify public commuters according to their destination once they have boarded. We also need to come up with a mechanism to not stop commuters at stops which are not their destination.
One way to achieve this is to re-imagine public transport as a subway or a rail based system with multiple speed tiers. Every speed tier has its own set of rails. There is the 0-tier at which stops are made. The rails for the 0-tier are closest to the platform to let passengers in/out. The subway compartments in higher tiers don’t stop at all. The different tiers, however, allow subway compartments to transfer between them. This may involve transferring a compartment between sets of rails.
Thus, a subway compartment may start in the 0-tier at a stop, but it will transfer to a higher tier once the compartment has started travelling and has achieved some speed. The transfer eventually will cause the compartment to be inserted in the middle of other compartments in a running train in the higher tier. Once the transfer is complete, the doors at the end of the compartment are opened and the passengers are requested to walk to the compartment representing their destination. Once the destination is about to arrive, the compartment for that destination transfers to the 0-tier (without stopping the rest of the compartments) and ultimately stops. It does so by first separating itself from the rest of the train and moving to the rails of the 0-tier. Once it is completely independent, it slows down and stops to let passengers in/out. This allows the compartments in the higher tiers to never stop, thus allowing passengers to get to their destination without having to stop anywhere.
The key piece is to build the transfer mechanism between tiers. However, it doesn’t look undoable and requires some clever engineering to get done. The other difficult piece is managing scheduling of compartments between different speed tiers. Other than that, the additional cost is in building the 0-tier rails at each stop. These 0-tier rails don’t need to extend very far (just enough to get the 0-tier compartments up to speed of the next tier).
Doing this for road transport is tougher because buses tend to shake a lot on roads which will make it difficult for passengers to cross over to the destination compartments. Also, building this over rails will allow much higher speeds than those achievable on roads which would incentivize public transport.