The " Park / Brake Interlock " is a feature on automatic transmission equipped cars , light trucks, and gas power motor homes.
Introduced, mid to late 80's, if memory serves, after a number drivers, drove through the back of their garages, by shifting into gear with their foot, mistakenly, on the gas instead of the brake.
The system needs to see the brake lights on to release the shift lever.
99DSDP 3884, Freightliner, XC, CAT 3126B, 300 HP /ALLISON 3060
2000 Caravan toad, Remco & Blue Ox.