Iragüen Paula, de Dios Ortúzar Juan
Department of Transport Engineering, Pontificia Universidad Católica de Chile, Casilla 306, Cod 105, Santiago 22, Chile.
Accid Anal Prev. 2004 Jul;36(4):513-24. doi: 10.1016/S0001-4575(03)00057-5.
Contemporary transport project evaluation requires the ability to value reductions in the number of estimated fatal and non-fatal accidents after project implementation. In this quest, we designed a stated preference (SP) experiment to estimate willingness-to-pay (WTP) for reducing fatal accident risk in urban areas. The survey was implemented in a Web page allowing rapid turnover and a complete customisation of the interview. The sample was presented with a series of route choice situations based on travel time, cost and number of car fatal accidents per year. With this data we estimated Multinomial Logit (MNL) and Mixed Logit (ML) models based on a consistent microeconomic framework; the former with linear and non-linear utility specifications and allowing for various stratifications of the data. The more flexible ML models also allow to treat the repeated observations problem common to SP data and, as expected, gave a better fit to the data in all cases. Based on these models, we estimated subjective values of time, that were consistent with previous values obtained in the country, and also sensible values for the WTP for reductions in fatal accident risk. Thus, the Internet appears as a potentially very interesting medium to carry out complex stated choice surveys.
当代交通项目评估需要具备对项目实施后预计的致命和非致命事故数量减少进行估值的能力。在这项研究中,我们设计了一个陈述偏好(SP)实验,以估计为降低城市地区致命事故风险的支付意愿(WTP)。该调查在一个网页上进行,该网页允许快速周转并对访谈进行完全定制。样本面对一系列基于出行时间、成本和每年汽车致命事故数量的路线选择情况。利用这些数据,我们基于一致的微观经济框架估计了多项logit(MNL)模型和混合logit(ML)模型;前者具有线性和非线性效用规范,并允许对数据进行各种分层。更灵活的ML模型还可以处理SP数据中常见的重复观测问题,并且正如预期的那样,在所有情况下都能更好地拟合数据。基于这些模型,我们估计了时间的主观价值,这些价值与该国先前获得的价值一致,同时也得出了降低致命事故风险的WTP的合理值。因此,互联网似乎是进行复杂陈述选择调查的一个潜在非常有趣的媒介。