Chapter II: The theoretical basis

Essential and optional traffic

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Within this four-fold classification of the use of vehicles there is one simple distinction of great importance. It is the difference between the use of vehicles for essential purposes in connection with trade, business, and industry, and the optional use of cars for private pleasure and convenience. The full importance of this will become clear later on; it is enough to say at this stage that the essential traffic is, in theory at any rate, calculable, for it is related to known or predictable trading and manufacturing processes, and to other predictable social and emergency services. The use of cars for optional purposes on the other hand depends on many uncertain factors, from the whim of the owner to the state of the weather, and it is often alternative to some other means of transport by which the journey could have been made.