Urban Transport Strategy. Management in Developing Countries John A Cracknell, страница 19

a)  regrettably information on the impact of traffic management strategies is limited. World Bank projects include Implementation Completion Reports (ICR) which present component impacts in conventional terms of economic internal rate of return (EIRR).  Most such evaluations are extremely general and tell little about the success or problems of individual schemes.  Additionally, there are practical difficulties in the assessments themselves (such how to deal with traffic growth over time). Regarding sustainability, there are no known time based reviews or evaluations.  The

ICR-type evaluations are likely to provide an incomplete basis on which to judge “success” of traffic management policies.  A case can be made for more systematic evaluations and this is discussed in subsequent Chapters but, given this limited quantitative data, the current Review is largely qualitative;

b)  to respond to such questions as “how many people are employed in traffic management”, “what is the level of inter-agency co-operation”, there has been the difficulty within the limited resources available for the Review, of obtaining representative data for a wide ranging sample of cities with similar characteristics.  It has not been possible to circulate world-wide questionnaires;

c)  traffic management undertaken for Bank projects is limited in coverage and scope and generally is concerned with a specific corridor or area or problem.  Rarely is the complete traffic management strategy for a city addressed in a Bank project and certainly it has never been addressed for large or mega cities.  Thus, even though traffic impact data for the Review are limited with respect to Bank projects, there are an even greater limitations on obtaining quantified traffic impact data city-wide.

1.4          Procedures employed in the preparation of the Review

1.4.1.      The Review was commenced in January 2000.  Resources for the Review were constrained and thus neither city visits nor comprehensive city case studies were possible.  Thus, the Review has been based on (i) consultations with representatives of international funding agencies (the World Bank, the Inter American Development Bank and to a limited extent, the Asian Development Bank), (ii) published documentation, (iii) internet-based consultations on specific issues with various city and agency representatives and NGO’s, (iv) previous experience of the consultant in the sector.  A draft report was submitted to the World Bank and Transport Research Laboratory (technical co-ordinators for DfID) in July 2000 for review and the current "Final Report" incorporates the comments made.  As required by the TOR, the Review has been assessed by a practising traffic planner-engineer in a “developing country”, this case, Brazil and incorporates comments arising from that review.

1.5         Form of the Review

1.5.1.      Traffic management measures may be divided into two basic categories^[2]:

a)  traffic management policies, measures and schemes which seek to improve and manage the supply of transport facilities with the objectives of improving traffic system capacity (in terms of persons and not necessarily vehicles) and/or quality and/or safety; and

b)  traffic management policies, measures and schemes which seeks to manage the demand for transport with the objective of ensuring that journeys are undertaken in the most efficient way for the community as a whole.

1.5.2.      These two strands of traffic management cannot be separated.  Ultimately, it is impossible to construct roads to cater for unconstrained demand by private cars.  A well managed city will, ultimately, have to embrace traffic demand management policies as part of an integrated transport strategy.  Demand management policies may be achieved through a combination of restraint (such as limitation of movement through parking or