Development of a Methodology to Estimate Parking Provsions and Occupation of Land by Car in Cities: the Case of Lille
P Palmier, CETE Nord - Picardie, FR
This study consists in elaborating a methodology to estimate the parking offer on-street and within blocks. This method allows to simulate the impacts, on the parking offer, of the setting of two-way roads, which were initally one-way and vice versa
This study is part of research from the french program PREDIT about the space consumption use by the different transport modes in an urban area. The paper focuses on an estimation of the global offer of parking places, either on-street or within blocks.
Currently, if public park-places offer is well estimated through operators and individual garages through census, on-street and in-block parking offer is globally unknown.
The method implemented, consists in collecting data on a stratified sample of land registry sections based on an urban typology. Thus, that typology has been elaborated with a statistical clustering on housing characteristics, household size, number of garages, year of construction and the proportion of build area. Then, a group of students have collected exhaustively the number of parking places for each street of a predefined land registry sections random sample.
Consequently, in order to extrapolate the sample results to the whole area, we have performed a dynamic inference trees analysis. This recursive partitioning is based on road characteristics, in order to model the number of parking places per km for on-street offer, and per sq m for parking within blocks. Keys factors that influence these ratios are the width of streets, the fact the street if one-way or not, and the urban cluster number, result of the urban typology, where the street belongs.
As a result of the model, a total of 675,000 on-street parking places was estimated on Lille Metropole area. On-street parking represents 4% of the built area, 27% of the road infrastructure area, and up to 32% in built area.
These ratios are higher in central sectors where the road network density is high. In addition, 420,000 parking places within blocks were estimated in a similar way, for a total of 1,250,000 parking places after adding garages and private parking places given by the council tax file.
Furthermore, the model can be use in planning. For instance, it allows to simulate the impacts, on the parking offer, of the setting of two-way streets, which were initially in one direction and vice versa. Finally, this approach provide a tool for decision makers in urban planning, in giving elements of land use consumption by car and to help them to elaborate their parking policy.
Association for European Transport