Driving Risk And Safety Control Strategy For Work Zones Of Expressway

With the increasing of investment for transportation infrastructure, the growth speed of highway mileage is rapid increasingly in our country; at the same time, the amount of motor vehicle and motor vehicle driver increase dramatically, which bring a serious challenge to traffic safety.Owing to the growth of expressway mileage and requirement of maintenance construction, heavy maintenance, reconstruction and extension for early freeway, the early breakage problems of expressway have occurred in a considerable scale, which must be solved by maintenance. Therefore, the maintenance of expressway becomes increasingly important. As an important part of expressway traffic system, woke zone is the given space of spot for maintenance. During the course of maintenance, the traffic of expressway is not required to interrupt. Thus, traffic problems in expressway woke zone become more prominent, such as reduction of traffic capacity, intensification of traffic delay, advance of fuel consumption and exhaust emissions and growth of traffic accidents. Owing to the influence of expressway maintenance, the lane number of work zone reduces and traffic capacity decreases. And also there are a lot of complicated traffic status such as vehicles merging, vehicle following and vehicle diffluence. As a result, expressway work zone has been not only an obstacle and dangerous source, but also one of space zones where recurrent congestion and various incidents occurred more frequently, which has brought large economic losses and mental stress and affected people's normal life. The safety of expressway work zone and its negative influence have become a focus that more and more engineers and researchers have to concern with. Therefore, the research on the risk identification, evaluation and control for expressway woke zone has great practical significance, which provides the theoretical basis and technical support for traffic safety security in maintenance construction.This dissertation is based on the project of Transportation Science and Technology of Heilongjiang Province "Research on Safety Security Technology for Expressway Maintenance Engineering in Heilongjiang Province" (200900001) and National Natural Science Foundation "Evolution of Vehicle Road Safety Coordination State" (51078167). On the view of highway traffic system engineering, this dissertation researches driving risk and safety control by considering the comprehensive factors of driver, vehicle, road and environment, complicated traffic environment and vehicle operation characteristics. And the research contents are as the following.(1) Theoretical framework and process of driving risk analysis for expressway work zone are proposed, which provides theoretical basis for risk identification, assessment and control. Based on the definitions of expressway, work zone, risk and road traffic system risk, the theory and method of risk analysis on expressway work zone are proposed by mathematical statistics, system analysis and risk analysis.(2) Section speed in expressway woke zone is verified in normal distribution based on the theory of mathematical statistics. According to the site layout, area division and vehicle operation characteristic of work zone, the data collection programme of traffic volume and vehicle speed is worked out. And then the traffic volume-time and traffic volume-space models of expressway work zone are proposed with 5min intervals in accordance with comparative analysis. And moreover P-P probability plots and One Sample K-S Test are utilized to verify the normal distribution for section speed frequency distribution of work zone respectively. And further Two Samples K-S Test is presented to verify the significance of differences on speed between different sections. At last, the spatial-temporal distribution characteristics and speeding characteristics of speed are further exploreed based on above analysis.(3) The models identifying driving risk of expressway woke zone are established based on DEMATEL and ISM. According to literature review and expert consultation, the index system of driving risk factors on expressway work zone is presented. And also Delphi method is utilized to determine the logic relationship between driving risk factors of expressway work zone. And then the methods of DEMATEL and ISM are adopted to establish the models to identify driving risk of expressway woke zone, which help to analyze the inter-relations between each pair of risk factors and determine the key factors of driving risk in expressway work zone.(4) The simulation evaluation model on driving risk of expressway woke zone is established by analyzing traffic characteristics and driving risk. And then after selecting risk measurement index and macroseopic traffic flow parameters, The Vissim software is adopted to simulate traffic flow in expressway work zone and collect the test data from simulation which is used to calculate the vehicle critical acceleration, the average risk level and macroseopic traffic flow parameters. And further the multiple linear regression model that can determine those contents presented above is constructed, which provides the scientific references for risk control.(5) To improve traffic environment and safety level in expressway work zone, the driving risk control strategy is researched. Based on speed limit signs and variable message signs, traffic organization measurements and safety management methods are proposed to control driving risk in expressway work zone combining information technology.The research results will provide theoretical basis and technical support for work zone scene management, safety evaluation, traffic organization and management scientifically and effectively.