Finding your way to a venue by automobile can be both stress inducing and potential career threatening. If you don't get there in enough time you could shorten your set up, sound check and prep time ultimately affecting your performance. More importantly you could damage your relationship with the client who is counting on you to entertain and impress their guests...and show up on time.
In my early years as a performer doing several gigs on a weekend I would pull out my trusty map book on the Friday night before and I would mark the destinations with post-it notes and stick the contracts in between the pages at the appropriate maps. Later on after the inter-webs became an accessible reality I started using Mapquest and would print out the maps the night before and staple the contract to them. Now with a GPS I have a new way of getting to a gig.
Each of these methods have their strengths. An old school map is a solid and reliable way of finding a location, but is a little weak on pinpointing an exact address as the street numbers are not printed in detail. The Mapquest/Google map print out is much more exact and can take you directly to a street or unit number but does not account for traffic and create alternative routes on the fly. And lastly the GPS is a real time location and direction finder that can instantly find alternative routes if you are stuck in traffic, but if you don't do your homework (or program the thing correctly!) it could take you on a longer route than necessary.
The best system?
I keep street maps of the major cities and towns where I might be traveling to here in Ontario, so I have a reliable physical reference handy to verify the GPS route and to get an overview of the route. The night before I travel I also print out a Mapquest or Google map of the journey to keep tabs on the GPS route and have an alternate in very off chance that my GPS unit completely dies on me (hasn't happened yet, but it could).
You may feel that this is overkill, but I don't want to take chances in getting to the gig in plenty of time to do everything I need to do to make the client and audiences experience the best I can.