Estimates of the number of foreign registered heavy goods vehicles on roads in Britain are not available. However, estimated numbers leaving the UK are published in table 1 of the quarterly bulletin, “Road Goods Vehicles Travelling to Mainland Europe”. A copy of this bulletin is available on the DFT website at:
http://www.dft.gov.uk/stellent/groups/dft_transstats/documents/page/dft_transstats_611744.hcsp