Research On Traffic Organization Optimization Of Highway Construction Area

In recent years,with the rapid development of highway construction and operation in China,the aging and damage of highway infrastructures have gradually increased the demand for highway construction and maintenance.During the maintenance and construction,due to the lane reduction and the change of the traffic path,the road capacity and vehicle speed of the construction sections have been greatly affected.Therefore,the purpose of this paper is to optimize the traffic organization in the construction area of highway,ensuring the traffic safety,reducing the accident risk and improving the traffic efficiency in the construction area of highway.In this paper,the optimization of traffic organization in expressway construction area is mainly studied from two aspects: layout setting and speed control of highway construction areas.Starting from relevant literature and basic theories,the accident risk level of relevant parameters in construction area layout setting were collected through questionnaire survey.Through the processing of the questionnaire results,the influence indexex of construction area layout setting of highway were quantitatively analyzed.Then based on the historical data of highway accidents,the costs of highway accidents are analyzed,and the cost model of highway construction area is obtained.And through the example the layout setting optimization process is analysed.Then,the speed control of the construction area of highway is studied.Taking the outer closed two-lane of two-direction and six-lane construction workzone of highway as the research object,the commonly used speed limit methods in the construction area of expressway are compared,and the dynamic layered speed limit method is determined.Safety and road service level are selected as indicators to determine the comprehensive evaluation method of speed limit mode.And the traffic state is divided into time periods,and the speed control of the construction area of highway under different traffic conditions is studied and analyzed.According to the variation of speed limit reduation,three speed limit modes of "F-S","M-M" and "S-F" are proposed.Finally,the speed limit strategy and the length strategy of transition zone in construction area are proposed according to each model in different density periods.Finally,VISSIM simulation software is used as the platform,and COM interface is used to simulate the traffic flow in different traffic states at different time periods by Matlab,and the traffic parameters of different schemes are output,to evaluate their own safety and road service level.The simulation results show that the MSDE value of "S-F" mode is 16.8% and 12.2% higher than the other two schemes in the low-density period,and the MSDE value of "M-M" mode is 7.2% and 4.3% higher than the other two schemes in the high-density period,which improves the safety of road operation.The simulation result of upstream transition area length shows that,in the low-density period,the value of road service level is little affected by the gap and transition zone length.In the highdensity period,with the increase of the length of the gap zone,the road service level increases first and then decreases.When the length of the gap zone is 250 m,the comprehensive value of road service level is 0.753,which is significantly better than the 0.837 or 0.840 when the lengths of the gap zone are 200 m and 300 m.