Quite a few people have driveway alerts set up using either a Dakota or a mighty Mule which they then connect to their smart things system by adding an additional device that has a Z wave radio. So the Dakota is doing the monitoring, and there is just Mimolite or dry contact device added to notify SmartThings.
The mighty Mule won’t match your use case, it’s specific to cars, but Dakota does make trip beam sensors. And the same approach would work for any trip beam sensor that you found that you could wire in a similar fashion to the radio device.
If you search the forums for Dakota you will find lots of examples. Here’s one:
It’s also discussed in the outdoor motion sensor FAQ, although you’ll have to read the whole thread to find the specific posts.