Effectiveness Evaluation of Bus Fleet Replacement Scenarios to Reduce Karaj Air Pollution

Considering the worn-out public transport fleet in Karaj city, it needs to replace the fleet with up-to-date standards. Considering the economic and environmental dimensions, the effectiveness of the measures taken should be evaluated. Therefore, achieving the goal of evaluating the change in the emission of pollutants based on each alternative scenario can help the authorities to adopt air pollution reduction strategies. The purpose of designing scenarios in this research is to estimate the effectiveness of scenarios in the field of replacing the fleet of worn-out single buses in reducing the emission of air pollutants.
Material and First, the classification of buses and units based on parameters such as different systems, year of production, pollution standard, type of fuel consumed and vehicle class have been studied at 1398. Then, scenarios of reducing standard pollutants were designed in two plans, replacing the worn-out fleet with a hybrid fleet, dual-fuel and with fuel consumption, with Euro 4 pollution standard, and finally the scenarios were compared with the basic scenario. Pollution emission coefficients and scenario design were calculated using the International Model of Mobile Vehicle Emission (IVE) model for passages, 1st degree arteries, highways and freeways, with slopes of zero and 22%.
The results of comparing the scenarios showed that by replacing the entire worn-out fleet in terms of age (to the new fleet, scenario four), the maximum reduction in emissions of standard pollutants was 40% (CO, 60% (VOC), 42% (NOX), 86% (Also, the results of the distribution of pollutants in the city of Karaj, with Arc Map software showed that the highest emission of pollutants is related to region 10, and the lowest emission is in region 1, Karaj city.
Discussion and According to the findings, the effectiveness of replacement scenarios of the worn-out fleet (use of hybrid, dual-fuel vehicles with Euro 4 fuel) in reducing the emission of air pollutants has been 40 to 80%. Pollutant reduction scenarios and strategies to increase air quality are useful for policymakers and researchers to better understand the current state of air pollution in the region and are largely operational, requiring timely funding and well-planned planning.