Metro trains such as BART can go 80 mph on a straight rail, so why does it often take longer to travel by light rail than by car?
Probably because: 1. The train must stop at every station on the way, and 2. Before you board, you must wait in the station for your train to arrive and then depart.
So using information technology, maybe we can fix this by breaking up each large rail car into many smaller independent cars; now each small car has two seats and is computer-guided nonstop from boarding to destination.
After all, modern metro cars already have one electric motor per axle and get their power from the rail, so why must they be attached to one another?
And the subway stations would be conventional, except now there would be an 'access lane', from which cars pull over, deposit passengers, take on new passengers, and take off to merge with the main rail. All other cars flow by continuously at a full 80mph.
You can imagine the user interface inside one of these cars. Step in, press your destination on a touch screen map, and read a book until you automatically pull over. If you're sharing the car with a stranger you may have to stop one extra time, but that's it. Almost like an elevator but with less waiting.
For those who need a larger car, 4-seater and 8-seater cars can be in the mix too.
There are a lot of other details I can address, but for now that's the basic idea.
BART info: (see link)