Mine are triggered by cross traffic
. They are MUCH harder to work with, but I am getting so I can time them a little by seeing if there is someone sitting there ready to cross, or how long the light has been green. I have noticed that if the light has been green for me quite a while and I can see a car sitting there ready to cross it will still remain green for a while longer. But if it has been green for quite some time and a car pull up and stops the light changes RIGHT NOW.
It's interesting, sitting out there with a stop watch and just watching cross traffic and what not would teach me a lot I am sure.
Brian