Does this mean that trucks are not allowed, or that trucks are the only ones allowed?
Good question, since the prefix –ל can either mean "to" or "for". In my understanding, a road closed to trucks would mean they're not allowed, while a road closed for trucks would mean they're the only ones allowed. So, can someone please tell us whether the translation can mean either one, or if it only means one and not the other?
I wrote: the road is closed to semi trucks.
Where I'm from, trucks almost only refer to pickup trucks, which I believe is טֶנְדֶּר.
משאית is not that though... it's a cargo truck or semi truck, right?
Near as I can determine, you appear to be right: משאית is a "freight" truck (lorry), while טנדר is a pickup or van.
We call lorries - Semis or tractor trailers. Trucks can be used for any type of truck, freight or pick-up).. But in referencing traffic/roads, trucks are assumed to be semis, because roads aren't usually closed for pickups. We call them truck stops as well. So unless one is in a rural area, I can't see the local population assuming the word would equate a Ford or Chevy pick-up.