Solution: (1) Using the image, it can be concluded that the line CD indicates that the car is parked on the way: 2.5-2=0.5 hours;

(2) According to the coordinates of point D (2.5,80) and point E (4.5,300),

Substituting y=kx+b, we get:

80=2.5k+b

300=4.5k+b

Solution:

k= 1 10

b=？ 195

Therefore, the resolution function corresponding to the line segment DE is: y =110x-195 (2.5 ≤ x ≤ 4.5);

(3) The coordinates of point ∵ A are: (5300),

Substituting into the analytical formula y=ax,

300=5a，

Solution: a=60,

Therefore, y=60x, and when 60x =110x-195,

Solution: x=3.9, so 3.9- 1=2.9 (hours),

A: The car overtook the truck after 2.9 hours.