Used mostly in Canada (cause no one else knows where the hell Alberta is), it refers to two cars driving side by side on a 4 lane highway or road. This is usually done by pricks who dont understand the concept of the left lane being the FAST LANE (or passing lane in the states). Eventually the person in the left lane smartens up and leaves. Also known as a cock block.
Man, Im sorry Im late but I was stuck doing 90 clicks on the highway behind an Alberta road block.