Technical Pinion Mounted Emergency Brake?

You can get a low volume or motorsport exemption in NZ .
The most common surge brakes here is hydraulic discs [due to a large percentage of boat trailers]
Cables and drums don't fare too well in salt water.

 

Pinion brakes are probably legal in my part of the world on pre-'95 vehicles, but hydraulic parking brakes aren't. The parking-brake system needs to be completely separate from the service-brake system.

There used to be a local kit comprising a check valve with a switchable bypass. You block the bypass and then step on the pedal to lock one pair of brakes. It was marketed as an anti-theft device, but some used it as a line-lock until some official got offended by that and they banned it.

 

Pinion mounted on my 1960 Rockwell 1-ton differential. My friend Joe Engelman in Independence fabricated this.