Exhaust emissions in residential areas with different street network configurations

摘要

Difficulties in reducing travel demand have created an interest in using design to reduce vehicle mileage per trip as well as pollution rates. Traffic generated in residential areas accounts for approximately 25% of private urban vehicle mileage. The objective of this study was to investigate differences in fuel consumption and exhaust emissions for built-up residential areas in relation to differences in the design of street networks. The configuration of streets greatly influences driving behaviour, and thus also exhaust emissions and fuel consumption. This study examined five areas with three different configurations: a traditional grid network, and designs feeding the traffic in from a surrounding street or from a centrally located street. Differences in total fuel consumption and amount of exhaust emissions were analysed. A traffic assignment model was used to calculate differences in average vehicle mileage. Real traffic driving patterns were used as input to an emission simulation model to calculate vehicular emissions and fuel consumption for the different areas. Linear regression analysis was used to investigate differences in pollution rates that could be explained by the configuration design.. The vehicle mileage per person was significantly higher in the areas with a surrounding street feeding in traffic. Configurations with centrally located feeding of traffic were found to have higher pollution rates. Taking both vehicle mileage and pollution factors into account, the study showed that configurations with feeding from a surrounding street generate higher emissions per person as well as higher fuel consumption. The higher mileage outweighs the lower pollution rates. The approach adopted in this study emphasises the importance of analysing pollution rates as well as vehicle mileage when investigating the overall impact of different planning strategies.