Comments on: Slower is Faster in D.C.

By: Christopher Monnier

Christopher Monnier — Fri, 01 Aug 2008 15:04:22 +0000

> “It is one of those cases where Adam Smith’s individuals pursuing their own best interests do not add up to Jeremy Bentham’s greatest good for the greatest number.”

I think this is because the individuals don’t know what their own best interests are. If a mechanism were put in place that directly linked individual financial incentives with the overall flow of traffic, I think Adam Smith would be vindicated. In other words, given the proper information and incentives, optimal flow will be reached more effectively if individual drivers are charged with acting in their own best [financial] interest than if a heavy-handed bureaucracy (i.e. cameras) exhorts top-down control.

By: Christopher Monnier

Christopher Monnier — Fri, 01 Aug 2008 14:13:31 +0000

The bit about variable speed limits made me think of a slightly different way to implement them. Instead of using traffic cameras to enforce variable speed limits (which seems like a heavy-handed tactic that many drivers will likely ignore), why not just charge drivers different rates for different speeds traveled? Assuming that a “pay-per-mile” tolling scheme is in place, drivers could be charged not only for where and how far they drove but also how fast they drove. As drivers approach a traffic jam, there could be one rate for traveling at 65 mph, another for 55 mph, and another for 45 mph, with the cheapest rate assigned to the speed that optimizes traffic flow.

This solution provides a transparent set of incentives for drivers to reduce their speed without resorting to some draconian enforcement mechanism (i.e. cameras that rigidly enforce lower speed limits).

By: Ted

Ted — Thu, 31 Jul 2008 20:01:40 +0000

I just found out about this book in a newspaper (Wall Street Journal, I think?). It is going straight to the top of my reading list. I have been living in the Research Triangle area of North Carolina for the past three years, being a transplant from Upstate New York. One of the biggest culture shocks of living down here is the absolutely astounding aggressive, or just plain poor, driving that goes on around here. I used to never see accidents or come close to death as a result of other drivers; now it seems it is a daily occurrence.

By: Lea Croteau

Lea Croteau — Thu, 31 Jul 2008 16:34:58 +0000

The germans have been doing this for years also. Around Munich where there is congestion, the electronic speed limit signs post variable speeds for the time of day and flow. We’ve all seen the person who insists on dodging and weaving through traffic to get ahead, only to see the same car some minutes later. I moved to LA recently, also having been from the WashDC area, and have noticed that at rush hour, the flow of traffic here actually works pretty well. And no cameras are necessary because of the amount of traffic. Thru traffic stays in the leftmost lanes, while merging and exiting traffic occupy the right lanes. Slow downs occur at on/off ramps, where people are changing lanes. Many drivers out here have the right idea: drive a slower, consistent speed to avoid the accordion effect. There are meters here too, as well as HOV lanes which are also home to hybrid vehicle traffic.