I think liability wise, you have to create a physical barrier in the front yard, as suggested by others.
I made a cheap wooden barrier off the end of my raised patio in the backyard out of old( free) skids/pallets that people were throwing away.
Even some stakes in the ground wrapped with yellow caution tape might give a visual barrier.
Perhaps put a big red “stop” sign on the fence, as I’m sure they’d recognize the significance of the universal symbol.
The liability is too risky if something happens while over ratio.