Cambridge Long Term Planning Committee


By Michael Salib
November 23, 2009

I'd like to suggest a discussion item for the upcoming long term planning committee meeting: Cambridge should implement a pilot program to study performance parking.

As I've mentioned before, several studies have concluded that a surprisingly large fraction of total traffic consists of drivers looking for parking. Drivers often have to spend excessive amounts of time seeking parking because it is not available. Sufficient parking is often unavailable because it is underpriced: either the city charges absurdly low prices for on street parking or the city compels private entities to offer "free" parking.

As I mentioned in an earlier email, this analysis is very boring and very well understood economics. For most types of products, when the government forces the price down, shortages naturally arise. In this case, shortages of parking are a problem, but they end up causing a much bigger problem: congestion.

Performance parking programs introduce market pricing into parking. Typically, the city sets a goal for what fraction of parking spots should be open during peak times in a particular area and then slowly adjusts the price of parking until that goal is reached. Inevitably, this results in an increase in the price of parking which increases revenues for the city. That money can then be used to fund other transportation improvements, such as public transport. This is exactly what happened in Ward 6 of Washington DC when they experimented with a performance parking program, as you can see from this blog post:

http://greatergreaterwashington.org/post.cgi?id=4117

Now, performance parking does have a cost: people who park their cars end up paying more. But such people benefit more than you might expect because they have to waste less of their lives driving around looking for parking. As drivers, they benefit more than anyone else from the reduced congestion. Beyond the basic economic logic of performance parking programs, they're also inherently progressive. This is because car ownership (and hence parking costs) tends to be far more common in higher income families while public transit usage tends to be far more common in lower income families. It is not quite accurate to say that performance parking programs are progressive; rather, they ameliorate one of the more regressive aspects of urban policy. In other words, they improve fairness.