One of the more popular tools modern cars are being equipped with are GPS devices or satellite navigation systems. It is widely known that such devices can pinpoint the location of the device on the globe to within a few feet. With this type of accurate location measurement, it would seem that the tool should be a fool proof navigation device, yet many claim that they are unreliable. So what is the truth?
Within certain parameters, satellite navigation devices are extremely accurate. For example: Harold has a satellite navigation system installed at his Honda Lincoln service location. His intention is to take a road trip to a location two hundred miles away. Keying in the his destination, the navigation system calculates a course for him complete with an estimated time of arrival. Following the directions exactly, he is amazed to discover that his arrival time is just a couple minutes off the computer’s estimate. Apparently the Honda Lincoln people gave him a superb GPS system.
Another driver, Michael, has a Honda Grantham service centre install a satellite navigation system because he wants to shave time off his daily commute to work. When it is time to leave for work, he inputs his destination and allows the computer to provide him with a course to the office. Fifteen minutes late, he stomps into work muttering curses on the shoddy navigation system the Honda Grantham people installed in his vehicle.
Why would the same type of system result in such completely different experience for different users?
First, satellite navigation systems are like maps. Their information is only as good as the last update. Major trends can change. A new highway can alter the traffic flow for an entire area, relieving traffic stress on some streets and dramatically increasing it on others. This is particularly true for surface roads because they are designed to carry less traffic than major highways and the traffic statistics upon which the computer makes calculations can change quickly for these side roads.
The algorithm used by a satellite navigation system is actually not necessarily designed to find the fastest or shortest route. It is designed to find the fastest, shortest route along the most major roads possible. The reasoning behind this is that the larger a road, the less likely its footprint or traffic flow have changed. The computer on a GPS will never be able to find a more efficient route than a knowledgeable human with current and complete knowledge.