Here's the story from the Houston Chronicle:
Houston's mandatory towing program has continued to reduce crashes on the city's freeways, according to a city-commissioned study released Monday.
The study examined the effect of the Safe Clear program from 2005 through 2008. It found there were 120 fewer accidents per month, on average, compared to the baseline year of 2004. The program began in January 2005.
Safe Clear gives one towing company the exclusive right to clear disabled vehicles from certain highway segments, eliminating the free-for-all competitive race to an accident scene by wrecker trucks.
Another program goal is to eliminate traffic congestion and secondary accidents caused by drivers slowing down to stare at a wreck. Under Safe Clear, the city tracks how long each towing company takes to respond to and clear a disabled vehicle.
Mayor Bill White launched Safe Clear as part of his mobility plan. The program met some initial resistance. Among other controversies, the mandatory tows cost $75, a provision that was later dropped.
The drop in auto accidents has saved the public more than $4 million a month in associated medical, insurance, and loss productivity costs, the study said.
“We've worked hard to make this program the success that it is, saving people money and time,” White said.
The new study could not discern if crashes declined because wreckers were no longer racing each other to a scene or because rubbernecking was reduced.
But the study did take into account other influences on the crash rate, such as rainy days, gas prices and the amount of traffic.
“It makes the program look exceptionally effective,” said Bob Stein, a Rice University professor who co-authored the study with Tim Lomax of the A&M Texas Transportation Institute. (Stein's wife works for the White administration as a City Council agenda director.)
The study showed a correlation between Safe Clear response times and the number of monthly accidents. The faster towing trucks responded to a call, the fewer accidents on the freeway. For every minute decrease in response time, monthly collisions dropped by 80 on all Houston highways, Stein said.
Link to gasoline prices
In 2008, a tow truck arrived within six minutes 89.8 percent of the time. The city's goal is 90 percent.
The study also found that response times lengthened as gasoline prices rose. Stein said that may be because wrecker drivers may have been patrolling less to conserve gas. (Drivers are also sent to crash scenes after being dispatched by police or TranStar, the regional traffic monitoring agency.)
The city has spent at least $67,000 studying the Safe Clear data.
Stein said his research has revealed that wrecker drivers used other tactics to learn about wrecks, such as stationing themselves near construction areas or telephoning each other. The city is conducting more studies on these methods to see if response time can be improved more through better training of drivers.