Externalities as objectives for DTM solving a dynamic multi-objective network design problem

There is an increasing interest in the effects of traffic on externalities. Research has also shown that in many countries the costs of external effects are even larger than the costs of delay. Therefore it can no longer suffice to view a transport system as feasible or optimal if only accessibility is considered. Dynamic traffic management (DTM) measures are often used to improve efficiency only, which means that traditionally the optimization of DTM measures considers the single objective of “improving accessibility”. However, these measures are potentially also powerful instruments to reduce emissions of substances related to air quality and climate, emissions of noise and number of accidents. Because there is a proven relation between traffic dynamics and these externalities, DTM measures can be used on a local level, but can also be used on a network level to influence route choice of road users and therefore influencing to what extent certain roads are used. To assess a certain deployment of DTM measures transport models can be used. Because traffic dynamics are important explanatory variables for these externalities and time dependent DTM measures are considered, the usage of a dynamic traffic assignment (DTA) model to assess a certain deployment of DTM measures is recommended. In addition, a DTA model can be used to overcome the widely recognized limitations of static traffic assignment in particular for oversaturated traffic conditions.