Love this. I’ve experienced bus bunching in several cities at this point (LA, DC, and now Seattle). It seems to be a known failure mode of metro transit planning. First step is understanding what your problem space looks like. Curious to know what anyone here thinks could be a solution. I doubt skipping stops is one. I suspect that speed controls are probably the way to go.
Edit: kudos to doing this in R. I’ve done other city analysis stuff in R and I keep coming back to it for one off things like this.
Skipping stops is something our buses used to do (rural Netherlands), this would usually happen if one bus was late so the next one was right behind it. Makes no sense for a full bus to stop when nobody has to get out when there's an empty one driving the same route right behind it.
Experienced bus travelers would often know when there'd be two buses in a row, too. And of course the bus drivers would point it out.
I wonder what it would look like if departure times were enforced in the don't-leave-before direction. Then giving enough time between scheduled stops that e.g. 90% of buses traveling that stretch can make it in time for that day/time combination. I realize that doesn't mean that 90% of trips will be on-time due to how failures will cascade, but it should eventually catch up due to the slack provided.
The big question is whether people will accept the increased latency (and total trip times) for less variance in waiting time and trip time.
As a bus rider whose drivers on one route sometimes do this, I loathe it.
The problem is that the route timing is designed for a specific traffic and ridership level. The actual time to run the route can vary by a factor of 3 or more depending on whether it’s before, during, or after rush hour.
The route timing is designed for after rush hour traffic levels, when it takes about 45-50 min to travel from my stop to my office stop. During rush hour, this trip can take 90 minutes. Before rush hour, it can take 20 on a good day.
So now, if I leave before rush hour, a commute that could be 20 minutes becomes 50 minutes. On a bus that is scheduled to arrive every 7 minutes - so bunching means waiting 15-20 minutes for a bus: LESS commuter time wasted by bunching than is spent sticking strictly to the schedule.
On buses that run even more frequently (one every 2-3 or 3-5 min during rush hour), this would be ridiculous. People aren’t catching the bus on a schedule - they just walk out the door whenever they’re ready, and expect a bus to turn up within a few minutes.
On a bus that’s scheduled to run once every 20 min (and you can wait an hour for a bus if they bunch), people are more invested in the schedule. I don’t actually trust the schedule at all unless within a few stops of the start of the route, and usually use the “just walk out the door” method anyway; but would appreciate and use the schedule if it were reliable.
So: as a bus rider I might support this, but they would have to fix the schedules. Create and enforce bus lanes. Run more buses - so that even when you get more riders than usual they can carry all the passengers at rush hour without being so packed that it takes 5 min to cram each new passenger aboard and half the bus has to debark to let someone off the middle. Then a little bit of traffic is less likely to create bunching.
I probably didn't do a good job of explaining it, but fixing the schedule was part of the suggestion. So for your example, rush hour timing would allow ~50 minutes between your stops, then after that only 20 minutes.
I suspect they would. Predictability in public transit is hugely important. People base a lot of their routines on these schedules. I also think enforcing stop/departure times is probably a much more elegant solution than controlling speed.
Buses are typically late due to variations in traffic. The solution is to prioritize bus traffic. Use dedicated bus lanes. Cars could drive in the bus lane, but must pull over or switch lanes if a bus is approaching. Traffic signals switch to green when a bus is approaching.
Not only does Pittsburgh have dedicated bus lanes, they also have dedicated bus roads; roads where cars are not allowed to drive on (many are deprecated light rail lines)
I don’t see this often in SF (at least on the E-W routes). Lots of factors though: overcapacity, mass-transit friendly population, express buses, sparse car traffic, linear routes, etc.
Edit: kudos to doing this in R. I’ve done other city analysis stuff in R and I keep coming back to it for one off things like this.