Inspired by Housing and Transit Roundup #3. I’ve been thinking about the bit at the end:
I’ve read the Wikipedia article on the phenomenon and the piece in Wired and seen the study results, and they imply very strange things. If a 10% increase in capacity within a few years creates a 10% increase in utilization, then that means there is essentially boundless long term demand for the road at that level of traffic.
If that is true, and the marginal car does not much change the traffic situation, why isn’t there boundless demand for the road with slightly worse traffic, increasing congestion now? If reducing capacity reduces utilization without harming traffic, how is that possible unless the experience of those still using the road got worse some other way? What is happening?
I think there are (at least) two things going on here:
- (I put this one in a comment) we’re paying in time here. And everyone has roughly the same amount of time to pay. There are ~24h / day but people also have to work, sleep, eat, wash, … and cost of that is different for different people. So different people have slightly different amounts of time they can “pay” for commuting. But I think differences are much smaller here than when people are paying with money.
- (this clicked today) travel time (in cars) is very much not linear with the number of people trying to travel. When you start adding cars to an empty road it doesn’t change much at first, then everyone has to slow down a bit, then suddenly everything slows down a lot (I think, if I want to check this video is where I got the idea).
Maybe I want to write this up nicely. Maybe with a simulation? I don’t know if this is actually interesting for anyone.
Also this looks like a topic where someone probably already did all the work.
cashoyat 