The main disadvantages of public transport systems are the restrictions imposed on freedom of movement for their users travelling from outside the central and suburban business districts (CSBD). The use of a private motorcar provides a superior degree of freedom, with some restrictions on its parking location within the CSBD.

However, conventional petrol or diesel engine cars have been reported to be the main sources of urban air pollution in major Australian cities – pollutants such as carbon monoxide, oxides of nitrogen, sulphur dioxide, particles (up to 50 microns) and lead – as well as being considerable contributors to greenhouse gas emissions.

Some reductions in these emissions are possible either by improving the engine performance or by using alternative fuels (such as compressed natural gas, liquefied petroleum gas and hydrogen). However, the reductions are often only marginal and may come at a considerable cost. Improvements in the environmental impact of car emissions can also be made by introducing travel demand management (TDM) and the intelligent transport systems (ITS).

The most effective way of reducing pollutants is through use of electric vehicles (EVs), which are approximately 97 per cent cleaner than petrol-powered cars. Battery-powered cars were originally designed and produced in the late 1880s, and by the 1920s they competed favorably with petrol-fueled vehicles. However, as travel distances increased, the main drawback of an electric car – its capacity for storing sufficient energy in the battery – became apparent. While one kilogram of regular petrol stores some 11,860 watt-hours of energy, a conventional lead–acid battery can, at best, store about 44 watt-hours.

The revival of EVs in the 1960s, as a consequence of a sudden increase in the cost of petroleum-based fuels, led to the development of new types of batteries, specifically designed for the use in electric cars. Advanced batteries that show promise in this specific application include lithium–iron sulfide, zinc–chlorine, nickel metal hydride and sodium–sulphur, although they still suffer some drawbacks, such as bulkiness, relatively high expense and appreciably lower capacity of energy storage, in comparison with the petroleum-base fuels.

At present there is a substantial variety of commercially produced EVs, ranging from the modest Korean CT&T city-class electric car, to the American-made Commutercar Tango and, at the top of the range, the electric sports car Venturi Fetish, which sells for US$540,000 and can accelerate faster than most of the fastest conventional sports cars. The somewhat restricted range of even the most modern EVs compared with petroleum-based engines presents a significant limitation in the use of an electric car as a family or a general-use commercial vehicle. However, it is not a limitation if EVs are used as a private urban transportation system (PUTS).

The concept of PUTS requires that a customer be sold not a car, but a service, consisting of a relatively large fleet of electric vehicles and a dozen or more strategically placed service stations for these cars, located in and around CBD and, in large cities, in the major suburban shopping centres.

The car can be a two-seater, “spartan” interior design which is easy to clean and maintain. An ubiquitous “smart” credit card and a computerised service would ensure that the first available electric car from any of the service stations in the network, already fully charged, serviced and cleaned, would be made available on demand to the card-holder. A credit could be provided for customers who recharged the batteries at home.

The service should be very attractive to customers, who currently drive conventional petroleum-fueled cars to CSBDs and incur a substantial cost in maintaining, running and parking their cars in and contribute extensively to the air pollution of CSBDs.

Professor Alek Samarin FTSE is a private consultant and adviser in the development and implementation of the concepts of sustainable development. From 1980 to 1994 he was Director of Research at Boral Ltd and Professorial Fellow at the University of Wollongong, and was then was appointed Adjunct Professor with the Faculty of Science, University of Technology, Sydney (UTS). He is currently with the Centre for Built Infrastructure Research, Faculty of Engineering, at UTS.