The four lane street (San Antonio south of El Camino) near where I live used to just have painted crosswalks but after two pedestrians were killed in a short span of time they added the flashing lights in the crosswalk to the ones close to El Camino and Foothill, no one has been killed crossing the street in the ten years since even though traffic anecdotally seems to have gone up a lot (knock on wood).
And in fact, based on Google Street View imagery, it appears they are in the process of doing exactly that:
https://www.google.com/maps/@41.0919153,-112.0647278,3a,75y,...
My city has some crosswalks with big, obvious flashing lights similar to this, and they really catch your attention more. Some of them have button that immediately turns the flashing lights on so you don't really have to wait for lights to cycle like you do at a normal intersection, which probably makes them more effective.