I do concrete work. Every video you see of someone or something walking into super wet concrete it really doesn't matter. That's a 5 minute fix. Cars going into it though you have to figure out how to get the car out.
I'm really surprised by that. The last guy I worked with made such a big deal about putting up temporary guards. I think he just wanted to get in another hour or so of work.
Normally when you finish placing the concrete you always have extra in the truck. So we pour out a pile or fill up the wheel barrow with extra. So say a dog walks in it and the concrete is still really wet. You just grab some of the extra concrete with a shovel, toss it out into the holes, and run the bull float over it again. Concrete guys are really good at tossing something from a shovel and hitting their target haha.
Barricades are nice to just stop people from doing it in the first place but unless you're doing some solid barricades you always have someone who ignores them.
When the concrete is pretty hard but still wet enough to leave tracks is when it's more difficult to fix.