The woman, in her 40s, was asleep in her car in a lay-by at Dunnington, near York, when she was attacked.
North Yorkshire Police said the woman was attacked on 1 July, but they have only now obtained a description.
The driver is about 55 years old, 5ft 10in tall with blonde or light hair and a tattoo on his upper left arm.
His lorry was cream or white in colour, with red lettering on the side including the letters D and E.
Det Ch Insp Dave Ellis, of North Yorkshire Police, said: "I believe that fellow drivers may recognise the description of this man, or of his lorry, and will be able to provide information which will help to identify him."
Police investigating the night-time rape of a vulnerable woman have issued a description of a lorry driver they want to speak to.