速限、自我保險與駕駛行為之經濟分析

The Economic Analysis of Interaction Between Speed Limit、Self-Insurance and Driving 8ehavior

本文分析公路駕駛人在面對公路行駛速度限制時，如何在生命安全與時間生產價值之間作一取捨，並將基本模型延伸，探討速限對駕駛人最適自我保險決策的影響。研究結論顯示:1.在公路不設置速限管制下，不論公路駕駛行為是消費抑或生產性質，駕駛人一旦發生事故，在事故損失自負部份的邊際技用小於-1的前提下，即可找到一個最適的自我保險規模，以達到效用最大化。2.假設公路設置速限管制，當駕駛人降低速度，導致正的邊際所得小於事故傷害自付損失的邊際成本，同時減速也有增強自我保險邊際防護的效果時，駕駛人會隨行駛速度上限的施行，調降自我保險支出的規模，反之，自我保險的支出幅度會增加。

This article analyzed the tradeoff between life safety and time value, under the circumstance of speed limit. Basic model was then extended to 叫plore the effect of speed limit on drivers' optimal self-insurance decision. The results showed that: (1) Given that no speed limit was imposed, once the accident happened, drivers could find an optimal self-insurance scale to chieve maximum expected utility, on the premise that the marginal utility of deductible less than -1; and ( 2 ) With critical appeed limit, drivers' decreasing speed would not only cause positive marginal income to be smaller than the marginal cost of accident, but also enhance the marginal effect of selfinsurance, i.e. drivers would reduce self-insurance expenditure. On the contrary, if drivers increased driving speed, their self-insurance expenditure would increase.