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Report n°6: Urban Public Transport

Seeking "surface efficiency"

It is not only "captives" for whom accessibility to employment and urban services issues are just as important as energy and environmental issues. Loss of accessibility is harmful to the general economic efficiency of cities and the challenge for public transport is to satisfy energy and environmental demands without losing sight of general accessibility to employment and urban services. Although the problem does not arise in the central business districts of the large conurbations, which are densely served by underground networks, this is not the case in many medium sized towns (in Europe, some 250,000 to 1.5 million inhabitants) and more particularly in the suburbs and outskirts of the larger cities.

In such medium-density urban environments, the efficiency of private cars as regards availability (no waiting time) and speed is high. This is the sector where the environmental component of collective transport is most clearly evident since it is in that situation that the number of vehicles x km, caused by urban activity, is extremely high because of the long distances connecting the various urban functions. In this type of urban space, density is insufficient to warrant investing in a metro system.

This is also the case in the megalopolises of developing countries, where "American type" urban growth leads to very intensive road traffic while investment capacity is insufficient to create or extend metro systems.

And yet, increasing the efficiency of surface public transport, using mainly public land and roads, is the prerequisite for a redistribution of transport in favour of public transit systems. Apart from gains in accessibility due to good space coverage provided by the public transport routes, it is also up to frequency and speed to reduce the differential between resources (employment and services) made available to urban dwellers by the automobile or by public transport. In the Paris suburbs for example, the difference can be as much as 1 to 4 or 5 (which means that you can reach four or five times as many jobs by car as by public transport for the same duration of travel time) although using integrated exclusive rights-of-way and preferential treatment at intersections can bring the difference down to approximately 2.

This is clear evidence of the degree to which exclusive right-of-way for public transport vehicles, be they buses or trams, are the key to their popularity and a decisive instrument for redistributing transport in favour of collective systems.