The relation between motor traffic and liveability in residential built-up areas is usually rather strained. Separation of terminating traffic from through-traffic by infrastructural measures is often difficult to realise without causing a decline in the accessibility of the area. On the other hand, a good accessibility might generate substantial through-traffic with all its adverse impacts on liveability and traffic safety. Within the framework of the sustainable safety program, a study has been carried out to analyse the impact of various elements of a road network structure in a built-up area on accessibility, liveability and traffic safety. The elements of the network structure are: the number and distribution of access roads, the number and distribution of access directions, and the type of linking to the external road network. A simulation study for a large number of synthetic network structures shows that the impact of access directions is much larger than that of access roads, since it affects route choice more substantially. In addition, the amount of through-traffic is very sensitive to the type of linking to the external network. The simulation study clearly demonstrates the divergent and partly opposite impacts on accessibility, liveability and traffic safety. The relationship between the number of access directions and accessibility has also been tested in an empirical case study for four diferent built-up areas in the city of Enschede, the Netherlands. The results of the field study confirm the simulation results. The implications for the (re)design of access road network structures for built-up areas are discussed. In addition, recommendations for future research are provided. For the covering abstract see ITRD E128239.
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