Adaptive Assessment And Optimization Of Traffic Safety Facilities Of Road Network

Safety facility is more and more important and significant to promote driving adaptability and reduce accident loss. As the expressway network is gradually constructed, traffic volume network distribution and vehicles composition are changed. It causes that original design concepts and parameters of the associated facility do not fit in well with these changes, and the relevant functions are difficult to perform. In addition, current service facility and protection facility exist a great deal of problems in the process of optimization improvement, because the actual functional capability is difficult to quantify. Under the influence of the expressway network function, the above-mentioned problems are especially remarkable. Based on the Zhejiang expressway network, this paper analyses the characteristics of the traffic volume variations and accident, utilizes customer satisfaction theory and investigation chart method to appraise the protection facility and then optimizes the settings and management. As for the problems existing in protection facility, it has used the means of computer simulation experiments to evaluate, and optimized its structure and design. The main contents and results are as follows:1. Systematic analysis of domestic and international research on the safety facility, especially the related researches on service facility and protection facility and existential problems. Based on the Zhejiang expressway network, it has analyzed the variation of the traffic volume variations and vehicle composition, studied the characteristics and variation of traffic accidents, and put forward the main study object and problems.2. User satisfaction evaluation model (SCSI) of service facility based on the customer satisfaction theory has considered the service characteristics of traffic safety-facilities and users’psychological characteristics. With the6latent variables, such as user expectations, perceived quality, perceived value, customer satisfaction, industry image and user trust, it has designed18measured variables established evaluation index system and method,and then provided quantitative methodology for adaptability evaluation of service traffic safety facility 3. The evaluation result of service facility shows that service and user’s perceived quality of the4aspects which are position, information systematic, information continuity of traffic sign and effectiveness of other service facility, have a strong correlation. Dissatisfaction with these services leads the perceived quality to score low, and then affects the total satisfaction of expressway to the user, so we should focus on improvements to these services. From the above4aspects, it has researched on information optimization of the service facility and presented optimum design and management program for multilane expressways.4. Based on the seamless requirements of Zhejiang expressway safety protection facility system, the entire road safety protection facility should be considered as a whole. It’s designed as a unified security standard and set the components of safety protection system in order to maintain the seamless connectivity of protective properties. It has also carried on evaluative research of the protection facility through computer simulation tests.5. Computer simulation evaluation result shows that, the current Zhejiang expressway safety protection performance does not meet security requirements, such as modular concrete barrier,2m column corrugated beam barrier and triangle side protection facility. By means of simulating calculation, the optimal design program proposed has made the protection performance meet requirement. Transition structure proposed in this paper between SB-class and SA-class road side corrugated beam barrier can oriented crash vehicles smoothly. The attitude of vehicle is normal, and it has not appeared overturned, stumbling block and so on6. The management and support of Zhejiang expressway traffic safety facility should be carried out from the following3aspects:rational planning and design, district management integration, strengthening the facility maintenance.