This is really a cool idea that would help in avoiding a collision. In an effort to reduce physical traffic signage and accidents, light show company Laservision are experimenting using a sheet of water with light laser projecting on it. This is done up at the Sydney Harbour Tunnel with more available in the city as well. The good thing about having such signage is the fact that it literally catches your attention. If the driver fails to notice it, he could still drive through it without heading into a collision. These pop-up signs has started off since 2007 and has therefore successfully prevented vehicles from turning into unintended traffic. I could see more of this being used in other parts of the world. In Singapore water sheet projection is used primarily for visual aesthetics. One example is the foundation of wealth in Suntec city where people had their messages displayed on the water foundation. Water projection is starting to see more relevant usage in our daily lives.