Physica A 537 (2020) 122686 Contents lists available at ScienceDirect Physica A journal homepage: www.elsevier.com/locate/physa Study on pollutant emissions of mixed traffic flow in cellular automaton Wang Xue a , Xue Yu a,b,* , Cen Bing-ling a , Zhang Peng a , He Hong-di c a Institute of Physical Science and Technology, Guangxi University, Nanning 53004, China b Key Lab Relativist Astrophys, Nanning 530004, Guangxi, People’s Republic of China c Logistics Research Center & Shanghai Engineering Research Center of Shipping Logistics Information, Shanghai Maritime University, Shanghai 200135, China article info Article history: Received 20 April 2019 Received in revised form 18 August 2019 Available online 18 September 2019 Keywords: Emission Pollutant Mixed traffic Cellular automaton abstract Based on mixed NaSch traffic flow model and the empirical formula of automobile exhaust emissions, emissions of particulate matter (PM), CO 2 , NO x and volatile organic compounds (VOC) are investigated with consideration of the different movement condi- tions, mixing ratios, the maximum velocity and lengths of vehicle. Pollutant emissions are determined by traffic characteristics from free-flow to congestion. Emissions of mixed traffic increase with the mixing ratio increasing. The impact of traffic state on emissions is discussed in detail by introducing the distribution functions for three types of motion states. Results show that decelerating vehicles discharge the most pollutants even if accelerating and decelerating vehicles in the congested state have a great impact on pollutant emissions in the mixed traffic flow. The effect of the maximum velocity and the length of vehicles on emission are investigated, respectively. It is found that the maximum velocity of the short vehicles has a significant impact on emissions when the mixing ratio and length of vehicles are fixed. The larger the maximum velocity of the short vehicles, the more the emissions is, but the maximum velocity of long vehicles does not display obvious effect. When the mixing ratio is given, the longer the vehicle, the less the emissions are due to restrictions on the loop road. © 2019 Published by Elsevier B.V. 1. Introduction In recent years, air quality has become increasingly terrible. It is one of the important factors to condition global development. In the metropolises, the motor vehicle fleet and the increasing emissions of toxic pollutants by industrial sources, cause high concentrations of harmful substances that are responsible for low visibility and various respiratory problems [1,2]. The most of particulate matter (PM), CO 2 , VOC and NO X pollutants are caused by thousands of vehicles emissions [3]. Moreover, recent studies have shown that the tiny particulate matter (PM) takes on multifractal property and long-range cross-correlation behavior via analyzing data of the field measure in Hong Kong and Shanghai [4–6]. Vehicles emissions have unavoidable responsibility that cause hazy weather, respiratory diseases and traffic congestion [7]. In addition, it is the most pressing problem to improve city atmosphere quality by dealing with emissions (PM, CO 2 , VOC and NO X ) form transportation. The variables which determine vehicle emissions mainly are composed vehicle types and size, velocity, velocity limits, acceleration, queuing time in idle mode during red phase, queue length and traffic flow rate [8]. However, the traditional measure to calculate PM, CO 2 , VOC and NO X emission observes every moment * Corresponding author at: Institute of Physical Science and Technology, Guangxi University, Nanning 53004, China. E-mail address: yuxuegxu@gxu.edu.cn (Y. Xu). https://doi.org/10.1016/j.physa.2019.122686 0378-4371/© 2019 Published by Elsevier B.V.