The best point-to-point driving route comes from the people who drive them every day.
Embed a route recorder in the GPS navigator. Record the actual route taken by the driver between any two points. This can be done automatically, or as instructed by the driver. Some incentives can be given to the first contributors of the system. Once the driving records reach a certain level, the wisdom of the driving crowd will show its intelligence.
Whenever a new route is requested by a user, the GPS system can use the huge driving record from the drivers to compute the fastest, most convenient route, for that particular day and time. You will be able to obtain the special local road connection to avoid the highway commute traffic at 9am; you will get a different route suggestion at 9pm, or on Sunday; you will get inter-state highway 80 to Lake Tahoe on Friday, but highway 580 and 5 for your drive back on Sunday.
It will take some time to attract driving records and establish the network effect, but once it is established, it would be immensely powerful.
Note: I realized later that Dash Navigation has been pursuing intelligent navigation using the wisdom of the crowd for long, although with a slightly different approach.