Report on Evidence Showing Tesco’s Under-Estimation of Traffic Generation in their Planning Applications and the Resulting Implications for Predicted Traffic at the proposed Tesco Metro, Ashtead

24th April 2012


The issue of traffic generation in relation to Tesco applications on the Ashtead site has been looked at in depth over the past four years. The specific concern has been to predict traffic generation accurately for each proposed Ashtead store, with implications for parking need.

In this report we have put together information gathered over the past ten years, which has been collected independently by campaign groups throughout the country, on accurate surveys of traffic generated by Tesco stores AFTER they have been built, which are compared with Tesco’s predictions in their planning applications. These surveys were developed on guidelines specified by Planning Aid for London (an independent, government-supported planning resource organisation). This information raises major concerns that Tesco continually under-predict traffic generation in their planning applications and hence under-predict parking need.

In this report “traffic generation” refers to car counts of cars in and cars out per hour to each store.

The evidence suggests that Tesco often predict a figure of traffic generation which can be as low as one-quarter of that which can actually be counted at stores of equivalent sizes.  The car counts attached to this report are from six different existing Tesco stores.  They are Brent Park, Wembley; Colney Hatch, Barnet; Cromwell Road, Earl’s Court; Bulls Bridge, Hayes; Cowley, near Uxbridge; and Ruislip Manor, Hillingdon. (See attached TESCO scans 1 – 4). The car counts were undertaken by the Yiewsley Community Involvement Group; the Ickenham Residents’ Association; and Harefield Retailers’ Association, between 2006 and 2008.  The car counts were verified by Dr Prakash of the Britannia Planning College, Harrow, through Planning Aid for London. These surveys were successfully used as evidence against Tesco in four Appeal Hearings in the London Borough of Hillingdon – in the Hillingdon Circus Appeal (2007); in the Yiewsley Appeal (2008); and in two Harefield Appeals (2009 and 2011).

We suggest particular attention is paid to the Ruislip Manor (280 sqm) (See attached TESCO scan 7) and the Cowley (400 sqm) (See attached TESCO scan 8) car counts because these are only Express sized stores yet they generate well in excess of the number of cars stated by Tesco in their current planning application for the proposed Ashtead Metro (682 sqm), which is approximately 2½ times the size of Ruislip Manor and approximately 1¾ times the size of Cowley. Both Ruislip and Cowley are in high visibility locations similar to the proposed Ashtead Metro.

Tesco’s submission to the London Borough of Hillingdon and onward to the Planning Inspectorate for their proposed Hillingdon Circus and Yiewsley stores (both stores  being approximately 7,390 sqm) predicted a traffic generation figure of only 200 cars in and 200 cars out in their busiest hours. In order to refute these very low figures, Yiewsley Community Involvement Group surveyed traffic generation at the existing Bulls Bridge Tesco store at Hayes (7,927 sqm) and found a figure four times greater ie 800 cars in and 800 cars out per hour. (See attached TESCO scan 5). At the Hillingdon Circus Appeal Tesco then realised they had to produce a more realistic car count than only 200 in and 200 out.  Hence they went on to produce their own counts from Tesco at Bulls Bridge, Hayes (conducted by Borehams) which were approximately 400 in and 400 out. (See attached TESCO scan 6). This figure of 400 in and 400 out was eventually accepted by the Inspector.  However, Transport for London wrote to the Inspector stating that they no longer considered Tesco’s evidence of 400 in and 400 out to be valid and it was this dispute that led Tesco to withdraw their application at Hillingdon Circus mid Appeal.  The conclusion is that Tesco’s re-submitted figures of 400 in and 400 out in the busiest hour at Bulls Bridge were still only 50%  of that which was realistic. 

The five stores that were chosen for the surveys were those stores that were suggested by Tesco in a nine page rebuttal produced in answer to Yiewsley Community Involvement Group’s initial Bulls Bridge car counts.

The three campaign groups then went on to count cars from the existing  Ruislip Tesco Express (280 sqm) and Cowley Tesco Express(400 sqm). Ruislip Express opened in 2007 and took 40,00 shopping baskets out of the local economy (figure from the Ruislip Chamber of Commerce). Ruislip Express produced a car count of 204 in and 208 cars out for just 280 sqm of retail space in one hour on a Friday night, 6-7 pm!  This makes Tesco’s suggestion that a 7,390 sqm store in the two Hillingdon proposals (ie at Hillingdon Circus and Yiewsley) would only produce 200 cars in and 200 cars out laughable.

These figures suggest that Ashtead’s 682 sqm Metro could produce more than twice the car generation of an Express store of 280 sqm ie more than 400 cars in and 400 cars out per hour at peak times.

In their current planning application for Ashtead Metro, Tesco suggest peak 6-7 pm weekday car generation of only 90 cars in per hour and 92 cars out per hour.  When compared to the attached surveys showing the equivalent peak time in Ruislip (204 in and 208 out for a 280 sqm Express store) Tesco’s estimates for Ashtead appear to be substantially under-estimated.

As a cautionary note, Tesco habitually use their net floor space figure against the gross floor space of other stores.

Gaynor Brown.
Community Campaign Consultant.

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