The 2007 FWD correlation trial was held on the 24th and 25th April 2007 at TRL on behalf of the Highways Agency. This is the 8th mandatory FWD correlation trial to be held in the UK with the objective being to monitor the performance of all FWDs (and Heavy Weight Deflectometer, HWDs) operating on the HA trunk road network. The performance of the machine operating on specified test sections on the TRL small roads system (SRS). Only machines that are considered to have demonstrated satisfactory performance in the correlation trial are subsequently approved for use on the HA trunk road network