[paulgb]

> That's the fundamental argument against the assertion that traffic speed increases will offset the costs. It cannot be true, or people would choose to drive.

I think the mistake you're making here is assuming that the value of driving and the cost of congestion are the same to every driver.

For some people, driving is an elastic decision. They mode shift, or time shift to off-peak, or carpool, or combine errands in the city into one trip instead of multiple.

For other people, driving is necessary. They'll benefit from fewer of the first type of person being on the roads during peak hours.

[josephcsible]

> time shift to off-peak

One of the worst things about this congestion charge is that it applies even at off-peak times.

[paulgb]

It’s 75% lower off-peak though, so there’s still an incentive.

[timr]

No, I don't need to make assumptions about any of that. It's a complex interplay of factors (like any economic system), and everyone has their own reward function.

I'm just saying that if the marginal driver were still choosing to drive, then the system wouldn't work at all. That seems tautological?

The MTA has to set the price high enough above market that the reduction in demand is X%. Whether someone is driving because of speed, or comfort, or some other factor, the cost has to exceed their personally calculated benefit.

[paulgb]

> Whether someone is driving because of speed, or comfort, or some other factor, the cost has to exceed their personally calculated benefit.

It's a dynamic system though; as some drivers opt not to drive, the utility of driving for those other drivers increases. Yes, the market will find an equilibrium somewhere where some people will still drive, but that's kind of the point.