An element of sustainable transport policy measures is parking policy in Central Business Districts (CBDs). If space is not restricted, the planning objective is to provide sufficient parking places for the full demand associated with a site. However, in central city areas where space is scarce, it is now generally accepted that parking supply should be restricted to a level somewhere below the total demand. However, no information was found in the literature on what might be an "optimal" level of parking supply in such constrained situations. This study addresses the questions: is it possible to define a "sustainable target" level of parking supply in CBD areas, and if yes, what is that level? Parking provision and policies for selected Australian and overseas cities are compared to the performance of those cities in limiting the use of cars to access the CBD. From this, patterns in policy are found that indicate the degree of commitment by a city to reduce travel demand. A strong relationship exists between the ratio of long-stay parking spaces to full-time employees and the proportion of commuters travelling by car. From this study it appears that this relationship can be used to define a "sustainable target" level of long-stay parking supply for central city areas, once a mode split goal has been set. However, it must be recognised that this is just one element of the CBD parking policy, and further studies are recommended to investigate how a desirable level of short-stay parking supply can be defined. (A)
Samenvatting