In the development of AucklandÆs Regional Land Transport Strategy, three scenarios were developed for travel demand management (TDM) investment. For each scenario, an estimate was made of the resulting reduction in vehicle trips based on the benefits of similar programmes in comparable cities. To reflect each level of TDM investment within the Regional Transport models, adjustments were made to ætake outÆ trips removed due to TDM. Successive model runs were then used to determine the impact of reduced vehicle trips due to TDM on the regional network. The results of this evaluation confirmed that these initiatives are likely to generate environmental and safety benefits, but in a city with rapidly growing population and car ownership the effect is simply to slow the rate at which things get worse. For air quality and road safety, other interventions are available which have a much greater overall effect. By contrast, TDM initiatives have the potential to manage traffic congestion. Investing the maximum available funding in road construction does not result in a net congestion benefit, and nor does shifting investment from roads to PT. The combination of PT and TDM investment, alongside priority roading improvements, offers the best hope of managing congestion on AucklandÆs transport network. (a).
Samenvatting