As an aside I now use my iPhone with Google maps as my navigation aid on the bike and returning home this weekend it proved to be a good move.
I was heading North on the A1 from the Kent R2E and it came up on the phone that the A1 was closed and it gave me an alternate route through Doncaster missing the closure, added about 15 minutes. If I'd relied upon my Garmin 595LM and the matrix signs I'd have been caught in trapped traffic in the closure. The current live information on the phone saved me from all that grief.
I like using Google maps because I get live updates, it's intuitive and easy to use, I always have my iPhone, my Garmin is clunky in comparison. Google is always developing and adding features because they have multiple millions of users to keep happy, be like Dave use Google Maps.....