Your instructor should resign. He should not be spreading this false piece of pilot forum folklore which has never had any truth in it.
The issue with road landings is that they often have lamp-posts alongside, which are not all that much further apart then your wingtips
Me and a mate were chatting the other day as to if the safest place to put an aircraft down at night would be on a major motorway. Anyone have any idea if people have done it and been successful or not? Would one be in a lot more trouble than attempting to land in a field as you are putting road users at risk??