Study On Carbon Dioxide Emissions Of Traffic Delay In Road Maintenance Construction Area Based On LCA

Improving the carbon emission of transportation construction projects is an important part of human response to global warming and sustainable development.With the rapid development of highway construction in our country,it is very important to explore the problem of traffic delay carbon emission in highway maintenance engineering for the growing demand of highway maintenance in our country,and to realize low-carbon highway maintenance.In this context,this paper takes life cycle assessment(LCA)as a starting point to analyze the impact of road maintenance construction activities on the extra fuel consumption of vehicles.The relationship model of "speed fuel consumption" of traffic delay in maintenance construction area is constructed from the perspective of LCA.The model considers the correlation between the factors of maintenance project and the factors of traffic delay carbon emission.On this basis,the paper summarizes the construction mode and background traffic operation influencing the carbon emission of road traffic delay in the construction area: speed limit value,construction section length and lane closure form;vehicle type proportion,traffic volume,driver’s familiarity with the environment,etc.Finally,based on the method of carbon emission factor,the quantitative evaluation method of traffic delay carbon emission in the construction area of highway maintenance and repair based on LCA is proposed,The prediction model of "speed fuel consumption traffic delay carbon emission" in maintenance construction area is established.VISSIM simulation software is used to simulate the actual maintenance construction scene to establish the traffic simulation model;Based on LCA,the carbon emission measurement method of traffic delay is used to quantify the impact of traffic delay in the maintenance construction area,and optimize the traffic organization scheme.VISSIM and LCA are used for traffic simulation and emission modeling respectively.Quantitative analysis of the impact of traffic organization schemes with different influencing factors on traffic delay carbon emissions,and sensitivity analysis of all key influencing factors.The results show that the carbon emission of traffic delay has a positive correlation with the change of cart rate,traffic volume and the length of closed construction section,and a negative correlation with the change of speed limit;Under the same traffic volume,different speed limit values will seriously affect the difference of total traffic delay carbon emissions between the two closed Lane modes;The sensitivity analysis shows that the increase of traffic volume has an obvious exponential effect on the carbon emission of traffic delay.The traffic volume and the rate of large vehicles are the main factors affecting the carbon emission of traffic delay,while the length of the closed construction section and the speed limit value are the secondary factors,The key to reduce the carbon emission of traffic delay should be to control the external environmental factors such as traffic volume and cart rate in the maintenance construction area.Then,through the actual case of expressway maintenance project,the carbon emission sources of construction and traffic delay in maintenance stage are calculated respectively,and the carbon emission magnitude of the original traffic organization scheme and the comparison scheme is evaluated quantitatively.The results show that the traffic organization of the closed half width lane is the best way to reduce the emission,and the traffic organization optimization can reduce the carbon emission of the maintenance project by 7%;The influence of traffic delay carbon emission under different traffic organization schemes on the total carbon emission of maintenance stage is equivalent to that of maintenance construction.The research content of this paper expands the research content of the road LCA on the carbon emission of traffic delay caused by maintenance construction,It has positive significance for optimizing the life cycle carbon emission of highway maintenance engineering practice.