Alnwick town and county councillor Gordon Castle sustained multiple injuries after the incident on the B6341, at Humbleheugh, close to South Charlton, on August 22, 2014.
Coun Castle, now 68, had to be airlifted to hospital following the collision between his motorbike and a Peugeot, driven by Oliver Milverton.
Mr Milverton, who is 25 and now lives in Hampshire, had denied the charge, but in December last year at Bedlington magistrates’ court he was found guilty.
However, he subsequently appealed the decision and at a hearing at Newcastle Crown Court last month, the conviction was overturned. Mr Milverton said that he did not wish to comment.
Coun Castle, who has no recollection of the collision, said he didn’t wish to make a statement because an insurance case is ongoing.