So i click on the MAPS icon and then click the button with 2 arrows in the bottom left corner. I then put 2 addresses and then click route and it now shows me a purple route between the 2 addresses.

My question is - when you click the CAR button (bottom right corner) - some coloured lines get overlayed on the bigger roads - highways etc, some of the lines are green, others are flashing amber and red. What does this flashing indicate? And what does it mean when the route is gray color? Thanks!

RTFM, pg 84.....useless