The pits at the oil change places have covers to prevent people from falling in. If you have the ceiling height, the four post lifts are nice and lower cost than constructing a pit.
When I was younger I dreamed of constructing a shop with a pit. Then I realized what a resale liability it might be and decided that when I get to build that dream shop it will have 16 ft ceilings so I can put in a four post lift. Alas, that dream shop is nowhere on the foreseeable horizon.
Here in NC we have them, but they must have a widely-spaced net over the them to catch people. Workers can easily get their tools and parts between the spaces....
Gaseous fumes that are heavier than air will accumulate in pits like that. I think this was one reasons a lot of shops don't use them anymore. Any gas that is heavier than air is no substitute for air as far as our lungs and well being are concerned.
Looks like a more recently restored car parked over an old pit.Too much bling on it and too shiny to be a real period picture.I know of a couple pits around town here that still have those hinged covers to drive on.The two here in town probably haven't been used in over 70 years.They're also on wood plank floors just like the ones in that picture.Wood sides too,just like that picture.
I'm pretty sure that pits are not illegal here, but the OH&S rules and regs to have one make it financially exorbitant to have it, and therefore a hoist is a cheaper option.