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- Report n°1: The new constraints of urban development
Report n°1: The new constraints of urban development
Transport
In all the situations examined, the urbanisation of new areas is made possible by the everyday use of private cars. In developing countries, it is the more affluent who can afford to move from the high-density city centre to a more airy suburb, where the car is indispensable for daily journeys. In Europe, working-class families are able to own property, and in particular single-family houses on land in periurban areas, as the property there is less expensive, while owning a car is very much commonplace. Even in former communist countries, while collective housing was a positive representation of urban life, the datcha on the outskirts of the city, within driving distance, is assuming a more and more important position and one might well wonder if ways of life are changing. Finally, in the United States, almost 90% of home-to-work journeys are made by private car, this percentage being all the higher as the city has spread and its density has been reduced.
Declining urban density, the single-family house and private property are creating the new geographical conditions confronting today's public transport administrators. They have to succeed in offering a credible alternative to the private car, while at the same time having to try to take into account the expectations of potential public transport users as much as possible.
Transport and urban density
We recognise the scope of relevance of different modes of public transport according to the density of human activity or DAH (densité d'activité humaine). This is a sociological indicator defined as the sum, on a given surface, of the population and the jobs available there, divided by the given surface. This density varies, for example, from 1,200 in the most high-density zones of Paris, to 20 in the more sparse residential suburbs. Above a density of 300, the metro or RER would be used. Between 300 and 120, the tramway and light rail are the appropriate solutions. Below 120 and we enter the domain of buses and then minibuses.
For the lowest densities, which are those found in residential suburbs, there is currently no means of transport to rival the car, and even in the slightly denser suburbs, buses are not positively perceived as they restrict the user in terms of timetables and routes.
Furthermore, the other chief problem encountered in these districts relates to the changes involved in travelling. To go and work in the city centre, the inhabitant of a low-density zone often has the option of either using the car for the whole journey or taking the car or bus to a nearby bus or train station. So he will often have to switch modes of transport during his journey. It is often these changes, when going from one mode to another, that are viewed as an obstacle by the traveller. They are synonymous with waiting, fatigue, time wasting and discomfort.
Towards new modes of transport
To compete with the private car in these low-density urban areas, these two aspects must therefore be taken into account: new and economically viable modes of transport must be created within a dispersed environment, of which Créabus(1) is a prime example. However, it is also necessary to offer solutions to the changes involved in journeys, so that intermodal transport becomes an effective and attractive solution for the individual, and not just advantageous for the community. Developing transit zones into service zones is one initial response, in the sense that daily tasks can be carried out in those zones, thereby alleviating the feeling of time wasting. But other solutions must be considered, as the demand for mobility is growing rapidly, and the dissociation of places of living, work, shopping and leisure, the reduction in working time and the increase in demand for mobility for leisure activities and the reduction in commuter journeys are calling into question a transport system that is inflexible and becoming less and less suitable for our societies.
Furthermore, in the collective paradigm, the car enjoys a very positive image. It is associated with the idea of freedom and has taken on an extraordinarily significant role in the life of every family, in particular those that live on the outskirts. Inhabitants of residential zones no longer walk or cycle, and use their car for almost all trips, however small. We have seen that in Europe, one out of eight car journeys was over a distance of less than 500 metres! The car has thus become an everyday, individual, personal and personalisable object, a free service, as the driver does not count the cost of such small journeys: a facility.
So any new public transport services that hope to compete with the car must not neglect the aspects of ease of use and comfort, in order to finally tip the individual's choice towards public transport as soon as the service is consistent. Without any real concern for taking these aspects into account, the private car will always be the traveller's preferred option.
(1) transport on demand with a changeable route conceived by Connex: the traveller picks his destination and timetable.