One thing I've learned before using a route created by Google Maps is to "run the map" via street view. Here's a great case in point. On a planned trip to Seattle, I previewed a route that would take me from my hotel to a near by Gallery. The distance was short enough to travel on foot.
So I did as I always do previewed the route on Google Street view. I was surprised to see that Google had directed me down a less than hospitable alley way.
Not so bad during the daytime, but definitely not for a night-time stroll.