The Garmin nuvi 855 offers faster more accurate route calculation than the prior nuvi 850 on a 4.3-inch touch screen, according to Garmin. It offers a "Where to" option that allows drivers to give a destination through voice or touch screen. The unit improves recognition of unfamiliar intersections, road signs and junctions. It retails for about $500. Real-time traffic is available via the MSN Direct service for $49.95 a year, or for a one-time charge of $129.95.

GPS Navigation Units

GPS systems from Garmin, TomTom and others have evolved to a point where they provide detailed, accurate guidance to drivers.