When we drive on a highway, we change lanes. It's incorrect to say "change the lane" or "change the lanes".

When we drive on a highway, we change lanes. It's incorrect to say "change the lane" or "change the lanes".

Please look over your shoulder before changing lanes.

Please look over your shoulder before changing the lanes.

More examples:

When I change lanes, I always check my side mirrors.

You should always look over your shoulder to check your blind spot when you change lanes.

When I changed lanes, I did not see the motorcycle in my blind spot.