This is a pretty cool example of using technology to prevent problems. The video shows a system that cascades a sheet of water and displays a stop sign directly in the path of trucks ready to crash into a tunnel (because the truck is too tall).
The driver had ignored several less obvious signals that they were headed for danger. This is an application of one of my favorite management (and industrial engineering) concepts: mistake proofing. As I have stated before, often it is really mistake making more difficult rather than mistake proofing. This truck driver ignored the first several warnings and actually could have ignored this one. This system doesn’t physically prevent the error (the options to do this I can think of would be impractical) but this does prevent the errors in any reasonable case it seems to me.
It does seem the process could be improved a big by doing the cool shower stop sign when the truck still has time to turn off without a huge delay. From the video it seems the truck progressed to a point where getting it out of the way created a major traffic backup.
Related: Practicing Mistake-Promoting Instead of Mistake-Proofing at Apple – Visual Management with Brown M&Ms – Poor Results Should be Addressed by Improving the System Not Blaming Individuals – Cutting the Boarding Time of Planes in Half