PTC have developed a  calculation tool  that uses Census Ward data and allows site specific determination of predicted parking demand by entering data including the location (ward) dwelling type (house or flat) size (number of bedrooms) and the way parking is provided (allocated or unallocated).

Expected levels of car ownership and demand were calculated using Census 2001 ward data adjusted using 2011 household survey data. Corrected data took account of expected growth to 2026 using TEMPRO data.

The tool automatically calculates the unallocated parking demand and demand for visitors. By altering the allocation of parking the influence on the total parking demand is automatically updated so that the right balance of parking can be determined so that it is an efficient use of land.

Visitor parking demands are generally clustered at evenings and weekends. Often some residents themselves are visiting and therefore by providing unallocated parking spaces, a balance can be met. If there is additional demand generated by visitors and parking is solely allocated then on-street parking will exacerbate. Studies by Noble and Jenks have shown that the demand for residents is 1 for every 5 dwellings (20%). If more than 50% of parking is allocated at a development then this additional demand should be added. The tool automatically adds this demand.

The tool gives the appropriate level of parking provision and should be used as a guide. Some flexibility should be applied in determining the actual provision at developments a guide of +/- 5% should be appropriate but will depend on the location and be under discretion of policy officers and be supported with justification.

A revised policy and park demand tool was adopted by East Sussex County Council in 2012 and has been recently updated using Census 2011 ward data.

The tool using Census ward data by dwelling type, tenure and number of bedrooms to calculate parking demand with drop down menus for ease of use.

 Pelham Transport Consulting, 3 Mill Hill Drive, Shoreham-by-se, West Sussex BN43 5TJ