I actually have done something similar to this, since I had pretty clear view of the road infront and had my old android phone laying around,

Used to yolov5 to detect vehicles and deepsort to track them, also got a rough estimate for the speed of the pass

heres the two part blog i wrote about it

https://dharisd.github.io/posts/vehicle-monitor/

https://dharisd.github.io/posts/vehicle-monitor-part-two/