Cars on street, outside my motion zone, trigger camera at night

I have my security camera set up with 2 zones in my driveway/front yard. I have my sensitivity set up one higher than the lowest (Person). It works great during the day as nothing triggers the camera to come on outside my zones. But at night cars on the road trigger the camera to come on even though the road in not in either of my zones. If I put my sensitivity to the lowest setting (people) at night is does not trigger the camera to come on but it is kind of inconvenient to have to change this setting every night.