This is a case for Bill Hagan.
Responsible will be the city, because the city boards are not clear enough for the traffic and responsible will be the school self because the chain (maybe) use to be property of the school.
To add at the use or abuse of the chain, the school must have a written permission from the city to use this chain on that street at that time for some days in a week.
That will not give the school the freedom to use a chain that is not conform the international traffics boards.
Well, maybe Martin Barret knows also something about this subject.