From OpenStreetMap Wiki
|barrier = bump_gate|
|Drive-through gate used in rural areas to provide a barrier to livestock that does not require the driver to exit the vehicle.|
|Used on these elements|
|Tools for this tag|
is a drive-through gate used in rural areas to provide a barrier to livestock that does not require the driver to exit the vehicle, open the gate, drive through, and then close the gate. By contacting the swinging bump gate with the front of a vehicle and then accelerating, the bump gate is pushed open, allowing the vehicle to pass. This requires some skill to avoid the gate swinging back and striking the vehicle. Accordingly, a bump gate is unsuitable for long vehicles.
How to Map
Simply add the tag barrier=bump_gate to a new node positioned where the bumb gate is.