Jaywalking laws = conformity, authoritarianism, and the corporate capture of public commons I guess? I mean, I don't know that Chevy Chase would have thought of it in exactly those terms but it makes sense that walk/wait signs (which wee still fairly new even in the 60s) would be a natural thing for mild counterculture comedy to use.
But more likely it's a callback/homage/ripoff of some old slapstick bit we haven't seen.