Integrated Trunk Highway Service Level Assesment And Improvement Investment Decision Making

The integrated trunk highway service level is closely related to the highway maintenance investment.For a long time,the evaluation of highway service level is mainly for independent projects,which is not systematic and lacks comprehensive evaluation indicators.The evaluation results are not closely related to investment decisions,and the investment is more concerned with the road facilities themselves,while the driving comfort and driving environment were not properly considered.Therefore,the method of integrated trunk highway service level assesment and improvement investment decision making should be well understood.Firstly,the main influencing factors of service level were thoroughly studied,the thesis has proposed a highway service level evaluation method,which is based on 8 items of technical indexes,including driving speed,pavement wearing rate,dangerous bridge condition status,dangerous tunnel condition status,serviceability rate of facilities,pavement roughness,vehicle bump and greening rate,in the principles that various evaluation indexes are able to effectively cover various service facilities of highway,index data are acquired easily,and the evaluation indexes can be quantitated,by combining the highway development situation in China and the detection capabilities of different kinds of indexes and giving consideration to the factor of costeffectiveness.Secondly,the thesis systematically investigated index evaluation method applied in the proposed highway service level evaluation index system.Specifically,this thesis proposed a pavement wearing index evaluation model through theoretical analysis,three-track pavement texture depth detection,pavement wearing evaluation and mathematical analysis.Based on the large-scale vertical section elevation field data of pavement and results of field road jump evaluation tests,a vehicle bump index evaluation model was established.The accuracy of the road bump evaluation model established in this thesis is significantly higher than the methods in the United States and the United Kingdom.For the other six indexes,including driving speed,dangerous bridge condition status,dangerous tunnel condition status,serviceability rate of facilities,pavement roughness,and greening rate,the evaluation model and thresholds were determined by the existing research conclusions combined with the calibration of the model parameters.By analyzing the impact of each evaluation index based on analytic hierarchy process,the weight of each index was determined,and the highway service level was calculated based on the results and weight of each evaluation index.Then,the three-track pavement texture depth detection and data association analysis were carried out to establish a prediction model for wear ratio and pavement wearing index.Moreover,based on the Markov transition probability matrix,a bridge and tunnel condition prediction model was proposed on the basis of a mass of bridge and tunnel structure detection data and evaluation results acquired over the years.Next,the effects of different treatment measures on the 8 evaluation indexes were analyzed based on the national highway statistics report and questionnaire survey results.The unit investment cost effectiveness with different treatment measures was quantified,and the evaluation methods of different treatment measures based on unit investment benefit(ECR)indicators were proposed.Finally,this thesis put forward an investment demand analysis method,highway investment priority ordering model and highway network multi-objective investment optimization decision-making model to improve traffic condition,traffic safety,traffic comfort and traffic environment.Moreover,a utility function optimization model was established to determine the importance of different highway facilities.Besides,an algorithm of incremental utility expense ratio was proposed to solve the model.The validity of the model was verified by an example.Based on the researches above,an integrated service level evaluation and investment decision-making method of trunk highway has been established,which included the whole process of service level evaluation,service level prediction,service level promotion and maintenance investment optimization decision-making.It provided strong technical support for achieving the highway development objective of “Smooth,Safe,Comfortable and Beautiful”.