What is the best way to animate the camera path? I'm modeling a car driving along a road(speeds up, slows down, and stops at traffic lights to wait till the lights turn green, etc.) What is the best way to animate the camera path for the following scenario?


The camera starts moving from point A, and it takes 500 frames to get to point B. During this 500 frames, the camera first gradually speeds up, then moves at a constant speed, and finally slows down to a complete stop at point B.
The next 50 frames, the camera will stay at point B.
From frame 551, it takes another 500 frames to get to point C from point B. The camera experiences the same motion as described in #1 (speeds up, constant speed, slows down, then stop.)
Again, the camera will stay at point C for another 50 frames. 
Point C to D is a curve path ( added using Shift + A -> add path). I want the camera to move along the path from frame 1101 to frame 1200. The camera should have the same motion as before(speeds up, constant speed, slows down, then stop.)


What is the best way to animate the camera path in this case? Is there any Python scripts available and can be applied to case like this? Thank you all in advance for your replies.
Create a single path for all of the trajectory. On the camera use a Follow Path Constraint. select the Target path, check the Follow Curve box so the camera starys aligned with the path and animate the Offset value.



On frame 1 create a Keyframe at 0. Go to to frame 500, change the offset value so that the camera reaches point B and insert another keyframe. Move to frame 550 and don't alter the offset value and insert another keyframe.

Keep doing the same procedure until your camera reaches point D.





The graph for the camera movement in the Graph Editor shows how the camera starts at 0, picks up speed, decelerates to a stop and accelerates again... all of that because as default Blender uses Bezier interpolation.