Abstract:
Vehicular emissions have increased in recent years due to rapid growth in world traffic resulting in an increase in associated problems such as air pollution and climate change, therefore it’s necessary to control vehicle emissions. This study looks at the effect of road maintenance on vehicle emissions. The Highway Development and Management Tool (HDM-4) was used to find the effect of road maintenance on vehicle emissions. Key data collected were traffic volume and composition, vehicle characteristics, pavement characteristics and climate data of the study area. Two options were analyzed using the HDM-4 software; the base case or do nothing while the second is overlay maintenance. The study also showed a strong correlation between average roughness and yearly emission levels in both the alternatives. Finally, the study showed that proper maintenance reduces the roughness and emissions. The study showed that, average fleet emissions of CO2, CO and NOx in 2016 was 401.70g/km before the overlay of M2 motorway. An average yearly increase of total emissions of CO, CO2, and NOx is expected in terms of exposure to road users and the environment. After maintenance (overlay) of M2 in 2017 average fleet emissions CO2, CO and NOx are 396.79g/km at IRI 1.0m/km. Results showed that a unit decrease in IRI causes a decrease in fuel consumption.NHA interventions limits were found to be effective when strictly applied on the study road. Key Words:Vehicle emissions; Road roughness; IRI; Maintenance; HDM-4; M-2 motorway; Overlay; CO
