Well if you are travelling from London to Glasgow by car you'll avoid those moors. As the route once you are out of London would be M40, M42, M6, M74, M8. Though I would recommoned M40, M42, M6 (Toll), M6, M74, M8. Going via the M5 onto the M6 means you'll hit Birmingham and traffic can slow to a crawl around there. Once you get past Preston on the M6 (and certainly Lancaster on the M6) the drive up the M6, M74 is fairly east until you get to about Hamilton.