Urban Transport Strategy. Management in Developing Countries John A Cracknell, страница 9

Guidelines – some aspects of traffic management project preparation and implementation are new to many cities and thus cities lack expertise.  Project processing could be assisted by the development of guidelines for some aspects such as: (i) institutional arrangements, (ii) public involvement in traffic management, (iii) training, (iv) planning and procurement of ATC, (v) programmatic approach to traffic management components and (vi) monitoring.

Demand Management

All urban areas require a good road network and construction of additional road capacity or to correct deficiencies in the network can alleviate some of the effects of congestion.  However, new roads even if they are affordable, generate new traffic, and benefits will be offset by future congestion unless growth in traffic is managed.  Inevitably, demand management policies will be needed which will involve balancing increased cost of car use and making public transport more attractive.  The underlying rationale for demand management is that vehicle users should pay a realistic price which reflects the full costs of their journeys by a combination of direct charges (such as parking) and indirect charges (such as vehicle taxes on ownership and use).  Ideally the costs of journeys should reflect traffic conditions by location (e.g. city centres) and by time (e.g. peak periods) and should seek to manage demand such that facilities are used by vehicles in the most efficient way at all times.  Thus the objectives of demand management are to:

♦       reduce traffic congestion;

♦      reduce adverse traffic related impacts on the city environment.

♦       although not strictly an objective of demand management, policies which rely on pricing mechanisms can generate significant revenue which should be used to improve the transport system, particularly public transport, in parallel and integral with restraint measures.

Demand management policies and measures can be categorised in various ways but essentially comprise:

Parking controls and management - parking control is the most universally accepted demand management mechanism and is used to some extent in all cities; however, the main objective is usually to eliminate obstructions to traffic flow by parking prohibitions rather than to manage demand.  On-street prohibitions, while clearly necessary, require management of the released road space (e.g. for bus priority) or else increases in "through" traffic can occur.  Charged parking should be part of any traffic policy as free parking is a subsidy.  Charges are usually aimed at limiting car commuting to reduce peak traffic volumes but parking charges alone are unlikely to achieve the congestion relief effect required and furthermore, a parking policy will not be fully effective as a restraint measure unless the traffic agency controls a large fraction of all on and off street parking.  The traffic agency will need to co-ordinate charges for on-street, publicly available off street and private non residential parking within an integrated policy.  This is not easy to achieve, particularly controls on private non residential parking where some form of local taxes on parking places (such as “workplace parking levies”) are politically difficult and moreover must be passed on to drivers in some way to act as a disincentive to car travel.  In developing cities, the institutional aspects of parking - enforcement, corruption relating to collection of charges and fines, levels of fines, tracing offenders and so on - pose practical difficulties for implementation of a parking policy but increased use of private sector contractors has been successful in some cities.  A parking policy is essential to good traffic management practice and parking charges can raise revenue for financing transport improvements; despite the practical problems and policy, is likely to the starting point for demand management in most cities