| dc.description.abstract | Freeways form the primary traffic corridor in Taiwan, and traffic accidents are a major cause of traffic congestion. By increasing the speed of the processes for handling traffic accidents, unexpected delays and the risk of derivational accidents can be reduced. To shorten response time and improve the efficiency of accident processing, this study schedules and allocates police patrols using an optimization method to enhance traffic safety and order.
First, data of all accidents occurring on National Highway No. 1 and No. 3 in 2006 were collected. The accident characteristics, accident responses, and shift scheduling were analyzed using correlation coefficients and ANOVA. Following these analyses, this study determined the following two conclusions: (1) No relationship exists between the response time and accident severity; and (2) a significant and positive quantity relationship exists between shift scheduling and accidents. Additionally, every stage of the accident processing procedure was identified. These data will form the parameters of future research.
Second, through further research, the response time was found to be influenced by three factors, as follows: the accident characteristics, accident response, and shift scheduling, which interact with each other. Achieving optimal scheduling and dispatching under complex factors using only one method is difficult. Therefore, this study employs a two-stage method to solve this problem. The first stage involves creating a chance-constrained optimization model for scheduling by using the minimal patrol units to meet the demands of accident handling. The second stage involves creating a dispatch simulation, which can simulate the operation of a police car under current conditions and evaluate the effectiveness. Additionally, eight patrol patterns, including moving and stationary patterns, are also inputted in the simulation. Indices are established for response time, extra supportive patrol units, extra work hours, and utility.
Third, the Taishan platoon was chosen as the case study. The simulation results led to two conclusions: (1) the optimal patrol schedule occurs at a confidence level of 99 %; and (2) the optimal patrol patterns are achieved by c based on accident frequency and rate. These values are evaluated using a composite index that integrates response time, extra supportive patrol units, extra work hours. Additionally, the correlation coefficients among above three indices are positive and near 1. These results also imply that they follow the same trend. The results of this study can provide a useful reference for other traffic enforcement agencies affected by similar conditions.
| en_US |