They are the bane of drivers across Maryland, Virginia and the District: cameras capturing motorists zooming through red lights. On Friday, Virginia lawmakers voted to effectively shut off the cameras, in part because of a study by University of Virginia civil engineering professor Nicholas J. Garber and his colleagues. Garber shared his thoughts about the utility of such cameras in an e-mail exchange with The Washington Post.
Q Why do red-light cameras lead to more accidents? Isn't that sort of counterintuitive?
ARed-light cameras do not lead to an increase in all types of crashes. They lead to an increase in rear-end crashes, i.e., when a vehicle runs into the rear of the vehicle in front. This is not counterintuitive, as the tendency is for some drivers to accelerate when they see the traffic signals change to yellow, which may result in a rear-end crash if the driver of the vehicle ahead decides to stop. Also, red-light cameras may inspire some of those drivers to stop when they otherwise would have proceeded through the intersection.
Were you able to assess the damage done -- either in terms of injuries or car repairs -- from these rear-end accidents?
No. Unfortunately we have not done so because the data for this analysis was not available to us during the period of the study. We recommend in our report that this should be done. This is one of the reasons why we also recommended that the red-light camera program should continue for a year to allow us to conduct this analysis.
Aren't the type of collisions likely to occur when running a red light -- fast-moving crashes into the side of the car -- ultimately more dangerous than rear-enders?
We believe it is correct that angle crashes are more severe than rear-end crashes, as one of our data sets suggests this. Unfortunately, we did not have the necessary data to conduct an in-depth statistical analysis on which such a conclusion could be based.
Virginia lawmakers decided Friday to scratch any extension of the red-light camera program, in part because of your research. Do you think that was the right decision?
Our report recommended that the programs be extended for one year in order to collect detailed injury data. However, we certainly respect the right of the legislature to make its own decision.
Do speed cameras, designed to catch speeders, present any of the pitfalls that the red-light cameras do?
Similar pitfalls are public perception and acceptance.
