Overview
The building and zoning systems of the municipalities contain provisions laying down the parking range to be created in new and renovated buildings and changes of use. These orders refer generally to the relevant VSS standard SN 640 291 "Parking, limiting demand, offer".
The definition of necessary respectively the allotted parking space available is an important part of the transport policy and has far-reaching consequences on the profitability of planned and existing uses, transport nor to traffic pollution.
Acknowledging these aspects, the approach and the specific offer values for determining the parking demand and offer in new and renovated buildings and changes of use are elaborated. In determining the parking offer accessibility for pedestrians and cyclists, the opening up of public transport and the possibility of multiple uses should be considered.
The work forms the basis for the revision of the VSS standard SN 640 291.
Approach proposed to establish the park space available for new buildings, conversions and changes of use, taking account of accessibility for pedestrians and cyclists, the opening up of public transport and possible multiple uses. The results of the research are the basis for the revision of the VSS standard SN 640 291 "parking, limit demand, offer". As part of the work, a corresponding draft standard is created.
In this project, an iterative optimization process is developed, which allows the estimation of parking supply for a broad range of facilities and combinations of land use.
The first step of the iteration consists of a comprehensive analysis of the transportation situation; the catchment area of the facility and the time dependency of traffic generated by the facility is estimated. Based on the characteristics of the transportation system and the accessibility of the facility by various transportation modes, the share of each mode (modal split) is estimated. For the resulting traffic by cars, the difference between the number of cars arrived and the number of cars departed at a given point in time corresponds to the number of cars parked at this point in time. The superposition of the time-variation curves of parking demand for all land uses results in the total parking demand attributable to the facility at each point in time. This combined time-variation curve of parking demand implicitly takes into account the possibilities of staggered, multiple use of parking spaces.
In the second step of the iteration, the compliance of the parking supply and its generated traffic with the goals fixed in local transportation plans, the regulations concerning the environment, the capacities of the adjacent road network etc. is checked. If compliance with one or more of these aspects is not reached, supporting measures such as improvements of public transport services, improved parking management methods or a reduction of the size of the facility have to be taken and the first step of the iteration process has to be repeated.
The process developed in the study can be equally well used in the framework of approaches which limit the number of trips or the vehicle miles generated by a facility, but it has the advantage of providing the number of parking spaces demanded simultaneously.
Funding
Results
The project proposes an approach for the determination of parking demand and supply for new infrastructures, reconstructions and changes in land use, taking into account accessibility by other modes than car and staggered, multiple use of parking spaces. On the basis of the results of this study, a new version of the VSS-Norm on the determination of parking supply was developed.
The results of a survey of the methods used to determine parking supply by cantons, cities and communities revealed, that the current VSS-Norm "Parking; demand, reduced demand and supply" does not meet the actual requirements for the determination of parking supply any more. It is not suited for the estimation of the parking supply required for big facilities, which generally combine many different types of land use and activities (shopping, recreation etc.). There are various factors influencing the parking supply required by a certain facility, such as its size and type, local conditions, accessibility by public transport, cyclists and pedestrians etc.
More simple method based on standard values for the specific parking demand are proposed which can be used for small facilities and for housing projects. Standard values for specific parking demand are given for various types of land use. The extent of a possible substitution of car traffic by other modes (such as public transport, pedestrians or bicycles) depends on the accessibility by these other modes. Area types are defined by the quality of accessibility. For each area type a value for the minimal parking supply required and a value for the maximum number of parking spaces allowed are proposed. Where staggered, multiple usages are possible, an additional reduction of the number of parking spaces should be considered.
As a further result of the project, a draft version for the new VSS-Norm SN 640 281 is included in the final report.