Even if you changed the speed limit to a very reasonable 20 MPH, it would still need enforcement. A campaign in New York City and the UK is called “twenty’s plenty”. Photo by ddartley.
Just throwing this out there… There’s a lot of talk about speed cameras (and red light cameras) being a “money grab”, that it’s about making money more than improving street safety. (See my comprehensive review of what it means for Chicago that Governor Quinn signed legislation authorizing the City to install speed cameras.)
Let’s say you’re the administrator of a city that needs to do two things: 1) make streets safe to walk and cycle on, 2) receive revenue for needed services (like crime investigation, libraries, or road resurfacing).
To make streets safer, you can reduce the incidence of speeding, and reduce high speed traffic. You could make this happen in several ways with one or more of these strategies:
- Redesign the streets. Add curb extensions, landscaping, raised crosswalks, road diets, and more traffic calming techniques.
- Use human police officers to enforce existing laws. Possibly reduce the speed limit and enforce that as well.
- Use cameras to issue citations to people who speed in their automobiles.
Each one of these has a cost of doing business. For (1) redesign the streets, you have the cost of installation and maintenance. For (2) human police, you have the cost of paying police officers their wages and pensions (and their cars and other materials). For (3) using cameras, you have the cost of installing and operating cameras, and the systems to verify violations and issue citations. For both (2) and (3), you have the cost of courts that deal with the traffic violations (mainly for those who appeal their citation). There are other costs for each of these I’m not listing.
As the city administrator, you’ve got to cover these costs. Which one will pay for itself? Using speed cameras. And it will probably have a lot of money left over after covering the installation and operation.
I posit that using speed cameras has the highest calculable return on investment. The benefits realized by (1) and (2) are about having safer streets, meaning fewer crashes and fewer injuries. And (2), enforcement by police officers, returns revenue via tickets to drivers – but does this revenue cover the enormous cost of wages, pensions, and operations? The return is probably much lower than the rate of a machine that works tirelessly from 5 AM to 11 PM near parks, and from 6 AM to 10 PM near schools.
If the city administrator chooses to reduce speeding with strategy (3), have they thrown in the towel on using street redesign (which also has hard-to-measure quality of life benefits) or police officers?
It may be that potential revenues are a motivation to install speed enforcement systems, but might it also be that speed cameras have shown to reduce the incidence of speeding, and that speeding is related to injury severity in crashes, and that speeding is related to causing crashes?
Transportation planning is a major arena for doing cost-benefit analysis, but determining the costs and benefits, and adjusting them so they are comparable and on the same scale, is not a very transparent or discussed process.