I would add the following: display the average speed to the destination ALL THE TIME, not only on "average speed zones". One of the consequences of the approach would be (I hope) to cause drivers to modulate their speed based on the displayed average value, especially in urban areas. The reduction would improve overal trafic safety. After all, what's the point of driving at a relatively high speed on a few short, clear streches of urban road whose limit is 60 km/h if the estimated average to destination is only 16 km/h?
I would add the following: display the average speed to the destination ALL THE TIME, not only on "average speed zones". One of the consequences of the approach would be (I hope) to cause drivers to modulate their speed based on the displayed average value, especially in urban areas. The reduction would improve overal trafic safety. After all, what's the point of driving at a relatively high speed on a few short, clear streches of urban road whose limit is 60 km/h if the estimated average to destination is only 16 km/h?