Basic Principles Of Traffic Engineering

Press, Volume XCVIII, Issue 28822, 17 February 1959, Page 7

Basic Principles Of Traffic Engineering

The application of the established principles of traffic engineering was needed today if the handling” of traffic problems was not to descend to the level of armchair strategy, said Professor W. R. Blunden last evening.

Professor Blunden, professor of traffic engineering at the University of New South Wales, was reading a paper on “Traffic measurement—the basis for traffic planning and control,” to the conference of the New Zealand Institution of Engineers.

“Traffic situations in their prelent acute form have become apparent only within the last decade and there has been little systematic collection and analysis of the traffic data of the past,” he said. “The data that are recorded in the form of individual experience are highly coloured by personality. Furthermore, much of this traffic experience is far too -complex for accurate interpretation without recourse to basic fundamentals.” Even if the past records were complete, he said, empirical prediction of future trends would be dangerous, for the traffic context was a fast-changing one and the planning of traffic works a relatively long-term matter. “The only satisfactory way in which to plap with any degree of precision in such circumstances is to know something of the fundamental laws relating to traffic phenomena.” Basic Concepts

Among the concepts basic to a more quantitative approach to the impact of the motor vehicle on city business and transport problems, said Professor Blunden, were: Vehicle ownership index: The ratio of the number of people in any one area to the number of cars. In the United States it was; in 1956, 2.7 to 1. At the same time, the ratio in New Zealand was 4.13 to 1, in Australia 4.3 to 1, and in Britain 10.7 to 1. Traffic Generators.—Those community activities, such as factories, retail shops, theatres, or picnic grounds, which attracted a flow of traffic. Floor Space Index.—The ratio of the gross floor area in a building to the area of the land it stands on and half the area of the street fronting it. Degrees of Freedom of a Transport System.—A comparison of the relative parts played by public . transport systems and private cars. Relative Efficiency of Travel Modes.—A comparison of the efficiency of the two systems, public and private. Professor Blunden doubted whether the efficiency of the public transport system could approach that of the private car when the time spent in wailing, and the distance to be travelled on foot were taken into consideration. Parking Demand.—This involved consideration of such factors as the number of employees in an industrial building, the number of square feet in a retail shop, the number of seats in a cinema or restaurant. Peak . Loading Factors.—“ This is one of the most troublesome parameters in all traffic systems. It results in severe increase in the capital cost of traffic works.” Focal Point “The traditional city centre is the focal point for much of the interest and many of the activi-

ties of an entire metropolitan complex, in fact of a whole countryside or State,” said Professor Blunden. “However, the great developments in mechanical transport, particularly individual transport that have taken place in the last half-century have caused such an expansion of the metropolitan complex that there is need for many large satellite centres. “The era of dominance of the public transport systems restricted the number of such centres and favoured the concentration of all the spectacular development in the central business district. “The automobile, however, is rapidly encouraging decentralisation and many of the suburban centres are developing rapidly. When vehicle ownership becomes near universal suburban business centres are becoming just as inadequate to cope with parking demand and the superposition of through traffic upon local traffic as has the C.B.D. (central business district). Regional Centres The regional shopping centre specially designed for the separation of through and local traffic, and with adequate parking room, was now a necessity, he said.

An important criterion for planning schemes was that of minimising time, said Professor Blunden. “Time is perhaps the most valuable commodity that the individual possesses in this fastmoving twentieth century era. The success of toll roads is largely due to the fact that people will pay to save time.”

Some of the principles adopted in traffic planning, said Professor Blunden, were these:

The separation of through and local traffic. The provision of appropriate offstreet parking for all forms of land utilisation. / The separation of vehicular and pedestrian conflicts. Provision of terminals for public transport facilities and load-'

ing and unloading docks and ' bays for commercial traffic. The integration of public and private transport systems. The optimum utilisation of existing facilities. The recognition of the fact that • highway and traffic facilities were revenue earning. The application of “needs” and benefit/cost studies for determining the allocation of funds and the priority in spending them respectively. There was clearly a need in a metropolitan area for a single body with responsibilities for the planning, over ; all design and operation of traffic said Professor Blunden. Details could well be left to other authoritiessuch as the police and highways departments.

The over-all planning of public transport systems should be included within its powers and, in town planning, perhaps the communications should be planned first and other developments, follow from them. , He had not attempted to discuss New Zealand said Professor : Blunden, adding: “Although fundamental laws have, been developed and many useful formulae have been proved, the constants and- boundary conditions that perpnit actual answers to be given can be obtained only from on-the-spot surveys.”