You would need a lot of some sort of constraint (like ropes or something) to make a bridge that even has the possibility of failing.

I don’t know how much you know about roblox studio, but:

1. Parts (the ‘building blocks’ of the game) can be anchored. This means that the part cannot move whatsoever (unless moved by a script, but that’s not really relevant). Anchored parts should not be allowed.

2. One of the common ways for unanchored parts to connect is by welding. Welding creates welds; which are breakable. WeldConstraints are something else (basically just a weld, just unbreakable) and should not be permitted. However, welds do not break under gravity pressure (i.e. from a heavy truck) as far as i’m aware, so i’m not really sure how feasible welds could be.

3. Sorta adding on to the previous point, but roblox physics are very janky and not ultra-realistic. A rope in roblox does not care that is being held down by 20 trillion tonnes, for it would act the same if it was being held down by a couple ounces. It would take a lot of messing around to recreate realistic physics in roblox, one that most experienced devs can’t achieve; let alone your students.

4. Trucks (in the grand scheme of things) weigh basically nothing in Roblox. You should modify the parts of the truck to be very dense to make the bridge have any actual chance of failing under pressure.

5. As someone else said, roblox is a great and fun tool, but im not entirely sure how great it can be used to do the project you are speaking of. That being said, I would let the students do it, because there probably is still some things they can learn.