One of the most annoying issues that drivers face on our roads is traffic. Some drivers have to sit in traffic jams every day they go to work where-as for others it may be when going on holiday or visiting relatives.
You cannot always avoid traffic but you can try and find out about traffic that has already built up so you can plan to avoid particular areas when planning your route. Google Maps offers a traffic overview showing you a colour coded system to show what the current traffic flow is like on these roads.
Some Sat Navs also have traffic information and they will re-route you to a better route should it pick up in delays in traffic ahead. Often these Sat Navs pick up information from the road agencies and also from other users of their Sat Nav, which feeds information back to a central database.