What does it mean when the red and yellow lights are on at the same time?
In the United States, this is found mostly in the Boston, MA area. It means that an all-pedestrian phase is in effect, and no cars are going thru the intersection. It was implemented before pedestrian signals came into use. If you are driving and see this, stop. Photos of this phase in use are at http://www.massroads.com/gallery.php?page=red_and_yellow . In some European countries, red-yellow precedes green and often coincides with the yellow phase for cross traffic. This might be to assist those drivers with manual transmissions (“sticks”). In other places in North America, a red-yellow is used on a four lens signal (red/yellow/green/green arrow) to substitute a yellow arrow when the green arrow is used right after the green ball phase. This is old and is now rare.
