If crosswalks are ever to evolve, using lasers is a must. At least that is what the following concept suggests.
Crossing the street turns out to be something dangerous, no matter if it is done on a crosswalk or not. A lot of pedestrians die this way each year, so finding a way to make crossing the street safer should be a priority.
Ho-Joon Lim, the designer of the Guardian crosswalk, considers that lasers would be a radical improvement to conventional crosswalks. A pole would be placed in each of the corners of the crosswalk. The principle the laser crosswalk works on is rather simple and intuitive. When the laser beams are projected across the street, pedestrians are able to cross in perfect safety. On the other hand, when the cars need to pass, the laser beams will form barriers along the road, thus preventing the pedestrians from crossing. The poles would also emit luminous signals in both situations, using the classic alternation of green and red. I think the idea is pretty simple, rather hard to implement and not very functional, however.
The major problem of this concept is that low-power lasers require fog or smoke to be visible. Use high power lasers that are visible at all times and you end up with something straight from Resident Evil.
One possible solution would be to install some sort of cameras on cars that would be able to detect laser beams from a distance. Upon detection, an alarm would have to be triggered, so that the drivers become aware that there is a crosswalk along the way.
In my opinion, the safest way does not imply lasers at all. Pedestrian bridges represent the best solution, since pedestrians and cars do not cross ways at all, in this scenario. The bottom line is that no matter what solution is chosen in the future, people should be taught to cross the street only in places that are designated for this. Even the Guardian crosswalk is useless, if the pedestrians decide to cross the street say 50 feet away from it. Basic traffic lessons should be taught in schools and remembered for all of our lives. That is, until someone figures out how to teleport across the street and beyond. That would truly solve our problems forever.