Lawpoolsri Saranath, Li Jingyi, Braver Elisa R
Department of Epidemiology and Preventive Medicine, University of Maryland School of Medicine, Baltimore, Maryland 21201, USA.
Traffic Inj Prev. 2007 Mar;8(1):26-34. doi: 10.1080/15389580601009764.
Speeding tickets are the most commonly used tool to deter speeders, yet little is known about how speeding citations affect individual drivers' behavior over time. This study examined the effects of being cited for speeding and types of legal consequences on drivers' subsequent speeding citations, which are an indicator of speeding behavior.
A cohort of 3,739,951 Maryland licensed drivers were identified and followed for one year. Drivers were categorized by whether or not they received a speeding citation in May 2002. Among those cited for speeding in May 2002, drivers were grouped by type of penalty (fines and points; probation before judgment [PBJ, which results in fines but no points]; or no legal consequences). The relative risks (RR) and 95 percent confidence intervals (CI) of receiving a speeding citation during follow-up were compared between drivers ticketed and not ticketed in May 2002, as well as among different penalty groups. Cox proportional hazards regression modeling was used to adjust for potential confounders, including age, gender, alcohol-impaired driving, and residence. Kaplan-Meier survival functions were used to examine timing of violations.
Young drivers and male drivers were more likely to receive a speeding citation. Drivers who received a speeding citation in May 2002 had almost twice the risk of receiving a speeding citation during follow-up, compared with those not cited for speeding that month (RR 1.6, 95% CI 1.52-1.68). Overall legal consequences had no significant effect on the risk of receiving a repeat speeding citation relative to ticketed drivers who escaped those consequences (RR 0.98, 95% CI 0.84-1.15); however, stratified analyses showed a significant decrease in repeat citations among females (RR 0.75, 95% CI 0.63-0.90) and drivers who received PBJ (RR 0.81, 95% CI 0.67-0.96). Kaplan-Meier curves showed that the study group of speeders had a significantly shorter time between May 2002 until receipt of a speeding citation than controls. Among penalty groups, significantly shorter times until receipt of another citation were observed among drivers escaping consequences or receiving fines/points compared with drivers receiving fines/PBJ.
Drivers who receive speeding citations are at increased risk of receiving subsequent speeding citations, suggesting that speeding citations have limited effects on deterrence in the context of the current traffic enforcement system. When comparing different penalties, PBJ is associated with a reduced rate of recidivism more than stronger penalties; however, it is unclear whether the reduction primarily is attributable to the penalty itself or to characteristics of drivers receiving PBJ. Increasing drivers' perceptions that they are at risk of being caught speeding may improve the effectiveness of speeding law enforcement.
超速罚单是用以威慑超速驾驶者最常用的手段，但对于超速罚单如何随时间影响个体驾驶者行为，人们却知之甚少。本研究考察了因超速被开罚单以及法律后果类型对驾驶者后续超速罚单的影响，超速罚单是超速行为的一个指标。
确定了3,739,951名持有马里兰州驾照的驾驶者队列，并对其进行为期一年的跟踪。驾驶者按2002年5月是否收到超速罚单进行分类。在2002年5月因超速被开罚单的驾驶者中，按处罚类型（罚款和扣分；判决前缓刑[PBJ，即导致罚款但不扣分]；或无法律后果）进行分组。比较了2002年5月收到罚单和未收到罚单的驾驶者在随访期间收到超速罚单的相对风险（RR）和95%置信区间（CI），以及不同处罚组之间的情况。采用Cox比例风险回归模型对潜在混杂因素进行调整，包括年龄、性别、酒后驾车和居住地。使用Kaplan-Meier生存函数来检查违规时间。
年轻驾驶者和男性驾驶者更有可能收到超速罚单。2002年5月收到超速罚单的驾驶者在随访期间收到超速罚单的风险几乎是当月未收到超速罚单驾驶者的两倍（RR 1.6，95%CI 1.52 - 1.68）。总体而言，相对于逃避这些后果的被开罚单驾驶者，法律后果对再次收到超速罚单的风险没有显著影响（RR 0.98，95%CI 0.84 - 1.15）；然而，分层分析显示女性（RR 0.75，95%CI 0.63 - 0.90）和接受PBJ的驾驶者（RR 0.81，95%CI 0.67 - 0.96）再次收到罚单的情况显著减少。Kaplan-Meier曲线显示，超速驾驶者研究组从2002年5月到收到超速罚单的时间明显短于对照组。在处罚组中，与接受罚款/PBJ的驾驶者相比，逃避后果或接受罚款/扣分的驾驶者收到另一张罚单的时间明显更短。
收到超速罚单的驾驶者收到后续超速罚单的风险增加，这表明在当前交通执法系统背景下，超速罚单对威慑的作用有限。在比较不同处罚时，PBJ比更严厉的处罚与再犯率降低相关；然而，尚不清楚这种降低主要是归因于处罚本身还是接受PBJ的驾驶者的特征。增强驾驶者对其超速可能被抓的认知，可能会提高超速执法的有效性。
