Cruising towards better air quality: The influence of Dynamic Traffic Management on vehicle emissions through driving profile improvements

Bad air quality is an increasing problem in most European countries and also in the Netherlands. A growing awareness of the effects of bad air quality on the environment and health has put the air quality issue high on the political agenda. Road traffic is one of the major air polluters in Europe. Especially near main arteries and in dense areas European air quality standards are being transgressed due to the presence of lively and much road traffic. Especially excessive concentrations of Nitro Oxides (NOx) and Particulate IVIatter (PM) cause problems. Dynamic Traffic Management (DTM) is often mentioned as one of the possibilities to reduce the polluting character of road traffic. These observations lead to the main research question for this study: To what extend can DTM measures contribute to an improvement of air quality? The goal set for this study is to investigate the possibilities to calculate the effects of DTM measures on air quality using microscopic traffic modelling. A calculation model can then be used to answer the main research question. Polluting character of road traffic Initially the characteristics of road traffic are investigated that cause its polluting character. Here fore, road traffic characteristics are subdivided into two groups: vehicle characteristics and operational characteristics. Literature study has lead to the conclusion that both vehicle characteristics and operational characteristics contribute significantly to the polluting character of road traffic. Vehicle characteristics that increase the polluting character are: Large vehicle weights, large engine sizes, diesel engines (PM and NOx), old vehicles (outdated environmental class) and poor vehicle maintenance. Furthermore the use of exhaust after treatment devices (catalyst converter and soot filter) has a large reducing effect off vehicle emissions. Operational characteristics that increase the polluting character are: highly dynamic driving with many acceleration and deceleration activities (transient state driving), extreme high and extreme low average speeds and many stops. Driving profile description In order to be able to investigate the quantitative impact of driving profile differences on emission rates, a driving profile should be described by characteristics that can be quantified. Each describing characteristic should comply with two boundary conditions; it should have a direct relation with emission rates and it should be measurable or calculable from a microscopic traffic model. All mechanical characteristics of vehicle operation lil