Wellington School of Medicine and Health Sciences, Otago University, PO Box 7343, Wellington South, New Zealand.
Accid Anal Prev. 2013 Sep;58:81-7. doi: 10.1016/j.aap.2013.04.036. Epub 2013 May 9.
Although previous research suggests that safety benefits accrue from periodic vehicle inspection programmes, little consideration has been given to whether the benefits are sufficient to justify the often considerable costs of such schemes. Methodological barriers impede many attempts to evaluate the overall safety benefits of periodic vehicle inspection schemes, including this study, which did not attempt to evaluate the New Zealand warrant of fitness scheme as a whole. Instead, this study evaluated one aspect of the scheme: the effects of doubling the inspection frequency, from annual to biannual, when the vehicle reaches six years of age. In particular, reductions in safety-related vehicle faults were estimated together with the value of the safety benefits compared to the costs. When merged crash data, licensing data and roadworthiness inspection data were analysed, there were estimated to be improvements in injury crash involvement rates and prevalence of safety-related faults of respectively 8% (95% CI 0.4-15%) and 13.5% (95% CI 12.8-14.2%) associated with the increase from annual to 6-monthly inspections. The wide confidence interval for the drop in crash rate shows considerably statistical uncertainty about the precise size of the drop. Even assuming that this proportion of vehicle faults prevented by doubling the inspection frequency could be maintained over the vehicle age range 7-20 years, the safety benefits are very unlikely to exceed the additional costs of the 6-monthly inspections to the motorists, valued at $NZ 500 million annually excluding the overall costs of administering the scheme. The New Zealand warrant of fitness scheme as a whole cannot be robustly evaluated using the analysis approach used here, but the safety benefits would need to be substantial--yielding an unlikely 12% reduction in injury crashes--for benefits to equal costs.
尽管先前的研究表明，定期车辆检查计划会带来安全效益，但很少有人考虑这些效益是否足以证明这些计划的成本通常相当高。方法学障碍阻碍了许多人尝试评估定期车辆检查计划的整体安全效益，包括本研究，该研究并未试图评估整个新西兰车辆检验合格计划。相反，本研究评估了该计划的一个方面：当车辆达到 6 岁时，将检查频率从每年一次增加到每两年一次的效果。特别是，估计了与安全相关的车辆故障减少情况，以及与成本相比的安全效益的价值。当合并碰撞数据、许可数据和车辆技术状况检查数据进行分析时，预计与从每年一次增加到每 6 个月一次的检查相关的伤害事故发生率和与安全相关的故障的流行率分别提高 8%（95%CI 0.4-15%）和 13.5%（95%CI 12.8-14.2%）。碰撞率下降的置信区间很宽，表明关于下降的确切幅度存在相当大的统计不确定性。即使假设通过将检查频率加倍来防止的车辆故障比例可以在车辆 7-20 年的使用寿命范围内保持，安全效益也不太可能超过每年向驾驶者收取的 6 个月检查的额外费用，不包括管理计划的总成本，每年为 5 亿新西兰元。新西兰车辆检验合格计划作为一个整体，无法使用这里使用的分析方法进行稳健评估，但安全效益必须相当可观——导致不太可能的 12%的伤害事故减少——才能使效益与成本相等。
