Red-light cameras hit speed bump
Thursday, September 18, 2008 12:48 PM
By MIRIAM L. SEGALOFF
ThisWeek Staff Writer
Pickerington’s developing plan to install red-light cameras at intersections along state Route 256 seems to have hit a speed bump.
Since April, the city has been working on a plan to install a photo red-light and speed-enforcement system at the intersections of state Route 256 and Interstate 70, Refugee Road, state Route 204 and Diley Road.
However, the Ohio Department of Transportation does not allow red-light cameras to be installed on traffic lights the state agency owns, including those at the I-70 interchange.
“Basically, the state has taken the position that we do not believe in the red-light-running cameras and do not support them,” said Brian Bosch of ODOT District 5, which includes Fairfield County. “So, on ODOT-owned signals, we do not allow them. What the city wants to do on theirs is up to them.”
Bosch is a Pickerington resident and member of the city’s planning and zoning commission.
I was very surprised to see that ODOT “does not believe in red-light-running cameras” in any circumstances. There are a number of conflicting studies out there regarding the effects of cameras, but the most convincing and statistically correct study is probably this one by the FHWA:
Safety Evaluation of Red-Light Cameras—Executive Summary
Publication No. FHWA-HRT-05-049
FHWA Contact: Michael Griffith, HRDS-02, 202–493–3316
This statistically defendable study found crash effects that were consistent in direction with those found in many previous studies, although the positive effects were somewhat lower that those reported in many sources. The conflicting direction effects for rear end and right-angle crashes justified the conduct of the economic effects analysis to assess the extent to which the increase in rear end crashes negates the benefits for right-angle crashes. This analysis, which was based on an aggregation of rear end and right-angle crash costs for various severity levels, showed that RLC [red light camera] systems do indeed provide a modest aggregate crash-cost benefit.
The opposing effects for the two crash types also implied that RLC systems would be most beneficial at intersections where there are relatively few rear end crashes and many right-angle ones. This was verified in a disaggregate analysis of the economic effect to try to isolate the factors that would favor (or discourage) the installation of RLC systems. That analysis revealed that RLC systems should be considered for intersections with a high ratio of right-angle crashes to rear end crashes, higher proportion of entering AADT [average annual daily traffic] on the major road, shorter cycle lengths and intergreen periods, one or more left turn protected phases, and higher entering AADTs. It also revealed the presence of warning signs at both RLC intersections and city limits and the application of high publicity levels will enhance the benefits of RLC systems.
…Even though the positive effects on angle crashes of RLC systems is partially offset by negative effects related to increases in rear end crashes, there is still a modest to moderate economic benefit of between $39,000 and $50,000 per treated site year, depending on consideration of only injury crashes or including PDO crashes, and whether the statistically non-significant shift to slightly more severe angle crashes remaining after treatment is, in fact, real.
Even if modest, this economic benefit is important. In many instances today, the RLC systems pay for themselves through red-light-running fines generated. However, in many jurisdictions, this differs from most safety treatments where there are installation, maintenance, and other costs that must be weighed against the treatment benefits.
In plain English, cameras tend to increase rear-end crashes and decrease angle crashes, resulting in a net economic benefit when cameras are installed at the proper locations. Red light cameras are not appropriate everywhere, but appear to be effective in some locations. When you consider that they pay for themselves, and can even generate revenue, they compare very favorably to other crash reduction methods.
Speaking of other crash reduction methods, I was impressed by the numbers in this study from Philadelphia. One of the more cost-effective ways to reduce red-light running can be to re-time traffic signals to provide more yellow time. If there is not enough yellow time, drivers with slow reaction times can get stuck in what is called a “dilemma zone,” a situation in which they don’t have enough time to stop safely but also can’t get through the intersection before the light changes to red. Philadelphia experienced a 36% reduction in red light violations (not crashes) by re-timing signals at three intersections to provide additional yellow time. That’s great, but even more amazing was an additional 96% reduction when cameras were installed. I don’t see anything about regression to the mean or spillover effects, but that’s impressive nonetheless.
So in summary, I don’t know if I-70 and SR-256 would be an appropriate location for cameras or not. It depends on the traffic volumes (which are probably high) and the ratio of angle crashes to rear-end crashes. But I’m surprised by ODOT’s refusal to consider the cameras anywhere. If they’re not willing to consider cameras, how much money are they willing to spend to get the same crash reduction factors with other safety improvements?