Gwyn Williams was over taken by the ambulance shortly before the crash in the New Forest and told ITV Meridian what he saw.
He had been driving along the A336 between Brockenhurst and Lyndhurst in the New Forrest.
More top news
Sussex Wildlife Trust is making an urgent appeal to the public to help protect dormice. Numbers have plummeted over the past 100 years.
HS2 is an expensive vanity project which must be scrapped, according to the TaxPayers' Alliance.
Friday morning's forecast for the east of the region