I have a few different loose ends to tie up from the first installment of Don't you hate traffic? .
First, since I've gotten thousands of emails asking about the title of this post, I'll address that first. It's a reference to The Simpsons (clip here) from back when the show was funny. (Yeah, I'm dating myself here.)
Second, how do you deal with privacy issues involved with tolls? If we use EZ-Pass, do we really want Big Brother knowing where you've been driving? I think there's a good way to get around this, which some politicians might not like: Sell EZ-Pass tags the same way we sell pre-paid disposable cell phones. If you buy an "anonymous" pre-paid unit with $100 on it and throw it away when you're done, then you haven't really given up much personal information.
Now finally, let's throw out this assumption that everyone is the same. Different people dislike traffic to varying degrees. Traffic makes me angry and agitated, but other people are in no rush to get anywhere.
So let's say we have a heterogeneous population and roads that aren't sufficient to accommodate everybody. One day I look outside and see 1000 cars on the road, which translates into 2000 units of traffic, using my super-secret traffic grading system.
Presumably, there are some people on the road who really value the road and/or don't particularly mind traffic. Perhaps they're willing to deal with up to 5000 units of traffic at this time. Every single one of them is on the road right now, because after all, there are only 2000 units of traffic out there.
There are also some people who are willing to deal with 3500 units of traffic, some people who can tolerate 2200 units of traffic, etc. and they're all driving now too.
But then there's a guy (call him Marginal Matt) who will only tolerate 2001 units of traffic. He's still driving (since there's only 2000 units) of traffic, but he's getting very little advantage out of having the roads available to him.
Here's the problem: If he would get off the road, there would be a little less traffic for the other 999 people. By deciding to drive, Marginal Matt is creating 2 units of traffic that all of those 999 other drivers has to suffer through and he's only getting 1 unit of advantage to himself.
In other words, he's creating thousands of units of harm and only getting one unit of benefit. Clearly, we need a pricing scheme that gets him off the road.
The optimal toll would balance these two effects. Switching to dollars, if the optimal toll was $10/mile, then there would be much fewer people on the road -- say 600 people instead of 1000. And if the toll is set correctly, then adding that 601st person would create exactly as much economic benefit to him and it would collectively take away from all the existing drivers.
One pleasant aspect of this is that only the people who value the roads the most will use it, and they'll be the ones paying for it. The people who walk to work and then pay an insane city income tax to help pay for roads are getting a raw deal under the current system. Their taxes could be reduced and we could have the drivers pay for the road. The result would be would be less traffic, more business activity (thanks to the lower taxes) and the roads would provide much more value to the residents.
Now I don't know what the optimal toll is, but I know that people do study this sort of thing and have attempted to put a price on traffic.
This system ideally would also end the "need" to subsidize mass transit. It drives me crazy to hear people say that we need to subsidize the subway in NYC since the alternative would be even more nightmarish traffic. When the idea of congestion pricing on roads is suggested as an alternative, people complain that that would increase the price of doing business, which would "get passed on to consumers".
While I don't have the time to delve into all the fallacies embedded in this nonsense, suffice it to say that if we priced roads correctly, a lot of people would take mass transit because it would be much, much cheaper than driving, and in the case of buses, it would be pretty fast (since traffic would be less severe).
In any case, how is it fair that my friend who walks to work has to subsidize the subway? How 'bout charging me for the subway ride that I take to work and charge Marginal Matt a buttload for the amount of congestion he's causing during rush hour?