I've needed a gated height restriction barrier for my model railway. I've also created a few other versions covering 3,4,5 & 6 metre real world widths. The maximum clearance as designed is a scale 2.2 metres (50mm) - you could shorten the uprights if you want a lower barrier.

I have included open and closed versions of each size.

The Maximum Height signs on my model were created in photo shop and printed onto thin card on my inkjet printer.

I have also included the gate post that the gate would be fastened to in the open position.

The barrier is photographed mounted on a piece of 2mm card just to keep it standing upright for the camera.

I sliced the file in Lychee and printed on my Anycubic Photon Mono X using Siraya Tech fast white resin.