If you are coming from Koyambedu approaching towards Vadapalani Signal, you will be passing through this signal, The worst part of the signal is that vehicles which are right at the front just before the white line will not be able to see the signal as the lamp post is hiding them, vehicles approaching from far away have trouble sighting the signal changing to red when they are close to the white line, you may say that there is one right at the top. Yes that one is for vehicles coming little far away.
One more thing which I wanted to mention is that, the same signal has one more disadvantage. The people who are on the left/right of the same signal need to wait more than 7 mins as compared to the main stream. Most of them cross when the main stream signal is still Green as there are few vehicles passing by. Few times I have encountered my self in trouble with jaywalkers and vehicles even my signal is in green.