Case study : Ile-de-France
Transport, particularly the car, takes up a significant amount of space in cities. Space, however, is a particularly rare and costly commodity in urban environments. As a result, excessive consumption of space can be seen as a nuisance in the same way as excessive noise, pollution or safety concerns are.
The relevant question is therefore whether modes of travel occupy too much space in light of the service they provide. As in many other areas of transport, supply needs to exceed demand by a wide margin. But how wide should this margin be ? Again, it seems that not only does the car use much more space than other modes per person transported, but that in addition it wastes this space, if one examines the number of parking spaces or stuctures that remain empty (a good third of the spaces in La Défense, for example), oversized highways (unused traffic lanes, huge roundabouts, etc.) and almost deserted secondary roads. Clearly more rigorous management of these spaces is required.
The report is divided into three sections. The first aims primarily to establish unitary values in all areas of consumption of space by transport in urban environments based on various modes of travel and motivations for parking and traffic movements.
The second is a systematic application to the case of the Ile-de-France. The case of public transport proved to be quite specific, and as a result only buses have been examined. Rail-based modes have been set aside for the moment.
The third offers two complementary areas for consideration, one exploring the key role of speed in converting time to space and the other examining the question of the cost of space consumption.
This research has at least three objectives. Firstly it aims to measure the importance of the consumption of space by transport in urban environments by identifying unitary values and applying them to the case of a large conurbation; the Parisian conurbation was chosen for reasons of data availability and its ability to act as a model. The research also attempts to understand the disparities between space consumption for parking and traffic movements depending on mode (walking, cycling, motorised two-wheelers, public transport and cars), motivations (work, shopping, leisure, etc.) and area (centre, inner suburbs and outer suburbs). In passing and this is not the least important objective it will offer a number of analysis tools, starting with a systematic distinction between supply and demand for space, the relationship between which can be used to calculate an occupancy ratio, revealing the most obvious levels and discrepancies.
PREDIT - order reference 06 MT EO12