You get the A for the class today.

Yes, all door boarding is the easiest and fastest way to dramatically reduce dwell time. Especially if you are using an automated fare card system. Cashless fare systems have been shown to reduce dwell times significantly, as well.

Eliminating boarding and alighting conflicts from passengers cueing up to get off, blocking those trying to board, can be reduced with the use of wider aisles, and/or wider doors, (hopefully both...that ability to walk "and" chew gum, so to speak....), has also been shown to be very effective in cutting dwell time.

Since this is a rail site, I note that these are all things that reduce dwell time (and travel time) are all things that are done on rail systems and that makes rail systems more advantageous for handling large passenger volumes, much more quickly.

Although, my particularly crappy local bus service is certainly a result of some truly bad planning, the buses running "nose to tail" problem isn't just a problem with bad planning, it is also about poor oversight and management of operations.

A lot of the "nose to tail" problem is quite often a problem with bus drivers who are intentionally running "dull" or "sharp" on their schedules, on purpose. Running "dull" or "sharp" is what they call blowing off their schedule to leave early or late to be able to run segments "nose to tail", and not have to stop all of the time to pick up or drop off those pesky passengers.

For years the unions fought using the real time on-board bus location detection systems we have installed to in any way monitor and/or discipline drivers. And, a good driver can always find a thousand ways to make an excuse for falling behind with today's congestion levels on a long bus route.

Math and science, ain't it great, measuring and testing, to analyze and make sense of what we see in the real world, to figure out how some of these things actually work....