Improved Route Calculation Options TomTom GO 300 will optimize its route planning based on the users preference:
TomTom GO 300 Volume Based on Car Speed Avoid changing the volume for noise generated by the speed of the car. A preference setting will increase / decrease the volume on the Tom Tom GO 300 of the voice instruction based on the change in car speed and engine noise.
View Route Best Options on Your TomTom GO before You Drive.
Specifications - TomTom GO 300