This paper describes the value of simultaneously planning all roads in urban areas, whether part of the hierarchy of arterials and collectors, or local roads. The distortions in decision making by evaluating arterials and the areas they enclose as a separate exercise are discussed. The results of traffic calming, including traffic displaced from local roads to arterials, should be seen as benefits rather than an additional cost in arterial B/C ratio calculations. Making area wide plans rather than separate arterial and neighbourhood area plans allows the full combined benefits of traffic capacity, crash reduction and calm conditions to be calculated as one exercise. Reference is made to methods of is made to methods of calculating the benefits of traffic calming, and to matrices giving maximum permissible flows and candidate traffic calming measures, as aids to the selection of design features. Two examples of network planning are described, firstly the Christchurch Central Traffic Plan and benefits in crash reduction and B/C resulting from the network changes, and secondly a theoretical network to demonstrate the effect of restricting traffic flows on local streets. (A)
Samenvatting