TfL carried out additional assessments in September after objectors queried its figures. An interim report submitted last week revealed that overall traffic levels including the effect of the bridge are estimated to be significantly higher than previously.
TfL technical witness Richard Smith told the inquiry: "We should replace the 2001 figures and I guess that is tantamount to saying that they are not reliable." The inquiry inspector asked TfL to finalise its figures by the end of the month. It must also submit updated evidence on the economic case for the bridge and the environmental assessment.
A TfL spokesman explained that the difference in the figures is due to traffic in Bexley growing at four per cent a year, higher than the London average of 0.3 per cent. "It is not so much that the figures are inaccurate, it is just that things have moved on since they were done," he added.
Friends of the Earth London campaigner Jenny Bates said: "I am surprised by how unreliable TfL's figures are. How can it talk sensibly about what they will be in 2016?"
Everyone who has appeared at the inquiry has been invited to review their evidence in light of TfL's findings. The inquiry was due to finish by Christmas but is now set to run into the new year.
Thames Gateway Bridge: Additional Counts and Modelling Work can be viewed via www.PlanningResource.co.uk.