Land Use Characteristics for Sustainable Urban Mobility
S Gori, M Nigro, M Petrelli, "Roma Tre? University, IT
The objective of the papaer is to evaluate the levels of density and the characteristics of mixed land use able to define sustainable urban mobility system.
In the last years important changes on urban features strongly modified the quantity and the quality of mobility system: the continuous spread of residences and activities have increased the length of trips and the use of private transport; the usual mobility habits have been changed by more complex behaviours (trip chaining). The automobile is considered the only transport mode and the use of transit became more and more unused with strong impacts on environment and sustainability.
Sustainable urban areas have to be appropriated for walking, cycling and for an effective transit system.
LAND USE AND TRANSPORT INTERACTION
Starting from the analysis of literature and remarkable examples in the world, different elements have been detected as the basics to develop sustainable urban mobility system (trips demand concentration, adequate transit network design criteria to improve the door-to-door travel times, mixed land use).
In particular transit stops have been identified as the key component to create walking, bicycle and transit as transportation options by using, in an adequate way, various elements of the street network and land-use intensity on the area. Two different transit-oriented development (TOD) can be realized around the transit stops of an high speed, high capacity transit system:
1. a classic transit village (about 0.35-0.5 km radius, high density);
2. a compact island (an extension of 300-400 ha, medium density).
To develop a TOD, two design concepts have to be clearly defined: the characteristics of mixed land use and the level of density to be adopted. In fact different studies report about the importance of these two concepts, but none clearly quantify them. The objective of the paper starts from this lack in order to evaluate the levels of density and the characteristics of mixed land use able to define sustainable urban features, where the use of public transport and other transport modes such as pedestrian and bicycle can be adopted as an alternative to automobile.
This study is based on an iterative procedure that permits to determine the equilibrium point between land use and transport recognizing specific and appropriate level of the two involved design concepts and identifying measures to assess the sustainability of urban development. In particular, the problem consists in the assessment of the O/D matrix constrained to the respect of the residual capacity of the multimodal transport system.
The procedure is applied to several districts in the city of Rome, different for the prevalent mobility system adopted, the distribution of transit stops, the parking supply, the pedestrian and bicycle facilities, the dimension and outline of the road network, density of residences and activities and other land-use dimensions (continuity, concentration, centrality, nuclearity, etc.) in order to validate the methodology.
Association for European Transport