Tuesday, February 27, 2007
Study of 3.7 million licensed drivers shows that ticketing does not reduce drivers’ likelihood of getting another ticket for speeding
Researchers at the University of Maryland School of Medicine have found that receiving a speeding ticket does not change a driver’s likelihood of being stopped again for speeding during the next year. In fact, drivers who received a speeding ticket during the study period had almost twice the risk of receiving a subsequent speeding citation during the follow-up period compared with drivers in a comparison group. The results of the study appear in the current issue of the journal Traffic Injury Prevention.
"Speeding is one of the most common and dangerous driving behaviors in the world," says Saranath Lawpoolsri, a graduate student in the Department of Epidemiology and Preventive Medicine at the University of Maryland School of Medicine and the lead author on the paper. "Inconsistent law enforcement, uncertain legal consequences, weak penalties and tolerant social attitudes are reasons that may explain why speeding is so widespread."
"Speeding tickets are the most commonly used tool to identify and deter speeders, yet the effects of getting a speeding ticket on a driver’s future behavior have not been adequately studied," says Jingyi Li, co-author on the paper who is also a graduate student in the Department of Epidemiology and Preventive Medicine at the University of Maryland School of Medicine. "Previous studies have shown that people with a documented history of speeding are more likely to be involved in motor vehicle crashes, suggesting that this high-risk behavior continues to occur even after convictions for speeding violations. Understanding the effects of speeding tickets on individual drivers is critical to improving traffic safety."
For the study, Lawpoolsri and Li examined data on more than 3.7 million drivers provided by the Maryland Crash Outcome and Data Evaluation System. The study group consisted of 15,814 licensed Maryland drivers who received a speeding citation in May 2002, while the comparison group consisted of 3,724,137 Maryland drivers who did not receive a speeding citation that month. Drivers were tracked from June 2002 to May 2003 for evidence of subsequent speeding citations. "Virtually every driver licensed in Maryland was included in the population that was studied," says Li. "We excluded only those drivers who had received a speeding ticket in the year before May 2002 in order to avoid spillover effects on behavior from past tickets."
Lawpoolsri and Li found that 11 percent of drivers in the study group who had been cited for speeding received another speeding citation during the follow-up period compared with five percent of those in the comparison group. When looking at the effects of legal penalties on speeding behaviors, the researchers found that the likelihood of receiving another speeding ticket was 12 percent among drivers who had opted to pay fines and received points on their driving records compared to eight percent among those who received probation before judgment (PBJ.)
In Maryland, drivers cited for speeding can choose either to appear in traffic court for a trial or pay fines by mail. If an offender pays by mail, the Maryland Motor Vehicle Administration will assess points on the driving record, which may result in increased insurance premiums. If an offender chooses to appear for trial, judges decide guilt and penalties.
PBJ is a common resolution in many traffic court trials; for speeding violations, a judge giving PBJ waives the points, puts the defendant on probation for a period of time (usually six to 12 months) and orders the defendant to pay the original fine or a reduced fine. "If the driver given PBJ is not caught speeding again during the probation period, then the violation is kept off the driving record, thereby avoiding insurance rate increases," says Lawpoolsri.
"PBJ appears to be the most effective penalty for speeding; however, we do not know if there are other contributing factors influencing drivers receiving PBJ and that these factors are responsible for the lower rate of repeat violations in this group," says Lawpoolsri. "If the effects of PBJ are due to the punishment itself, perhaps the experience of going to court and appearing before a judge has more of an impact on a violator than sending in a check to pay a fine. Future research is needed to learn more about the deterrent effects of PBJ."
According to the National Highway Traffic Safety Administration, speeding was a contributing factor in 31 percent of all fatal crashes in the United States in 2003. Excessive speed increases the crash risk by reducing a driver’s ability to negotiate curves or maneuver around obstacles in the roadway, by extending the distance necessary for a vehicle to stop, and by increasing the distance a vehicle travels while the driver reacts to a hazard.
"The current traffic enforcement system is like playing the lottery," says Elisa R. Braver, Ph.D., associate professor in the Department of Epidemiology and Preventive Medicine at the University of Maryland School of Medicine, who is based at the Charles McC. Mathias National Study Center for Trauma and Emergency Medical Systems. "The chances of getting a ticket on any one trip are low. To affect a behavior like chronic speeding, there needs to be a higher certainty of getting caught and punished. We believe that measures such as installing automated speed cameras on public roads should be evaluated to see if they provide stronger deterrents."
Dr. Braver served as Lawpoolsri’s and Li’s advisor on the study. It was carried out for a class on epidemiological research methods at the University of Maryland School of Medicine.
Data for this study was provided through Maryland’s Crash Outcome Data Evaluation System, a project supported by the National Highway Traffic Safety Administration to understand and improve traffic safety by linking state crash and injury databases.