Characteristics and distribution of greenhouse gas emissions from motorcycles in Hanoi, Vietnam

Abstract

Motorcycles contribute to the notable emission of greenhouse gases (GHG) and air pollutants in urban areas. These vehicles are the most widely used means of road transportation in Vietnam. This study is the first to use the EMISENS model in combination with the IVE modelling system to calculate greenhouse gas emissions from motorcycles at tier 3 in IPCC guideline. There are more than 8700 motorcycles circulating on the roads in Hanoi per hour. With the characteristics of motorcycles compiled, the average age of motorcycles is around 11 years, and each vehicle travels an average of 16.4 km per day with an average start-up frequency of 3.46. The emission factors of greenhouse gases CO2 and CH4 when running (erunning) were 72.55 and 0.24 grams per km, respectively. The emission factors for CO2, CH4 and N2O during vehicle start-up (estart-up) were 6.96, 0.53 and 0.0009 grams per start-up, respectively. Inventory emission data from 2021-2023 reveal that that motorcycles in Hanoi emitted nearly 4.6 mil tons of CO2e per year. Emission distribution is concentrated in inner-city districts and some residential areas at the intersections with provincial roads, national highways, and industrial parks.