What affordable outdoor camera could catch people littering by the road?

The plate is the tricky part. A moving car 50 feet away can be hard to read because of its speed and the camera angle, and nighttime makes it harder still.

If a readable plate is the main goal, look at a dedicated license plate recognition camera rather than assuming a general security camera will do it. Check how much of the road it can cover from your mounting spot before spending money.

Reolink is worth a look for a reasonably priced general security camera. Compare outdoor models and their fields of view against your mounting position. A wider view may show the littering, but don't count on it to make a distant moving plate readable.

Eufy has outdoor options with batteries and built-in solar, which could be handy if running power to that spot is awkward. Some models can record in the dark without an obvious light. Look for at least 2K resolution if detail is the priority, though resolution alone won't guarantee a readable plate.

If you have an old phone lying around, Alfred Camera can turn it into a basic motion recording camera. It could be a cheap way to see whether the angle catches the road at all. I wouldn't rely on a phone for a moving plate at that distance, especially after dark.

If you want coverage of more than one area, a multi-camera DVR kit is another option. H.View has kits with room to add cameras, including pan and tilt models. That may be more equipment than you need for one dumping spot, though, and the kit price alone won't tell you whether a plate will be legible.