u/Tits---McGee

My town has these "smart" turn signals so that if someone isn't in a turning lane, say, 3 seconds or so before the light change, no turn arrow appears and you just get a straight green. Fine, its a good technology and I am glad its there. But IF IT EXISTS....why cant it work in reverse? Why is the "turning off" of the green arrow tied simply to a timing metric and not to whether or not there are still people in the turning lane trying to turn? So many times I'll be like the 5th car, 4 get to turn (its a very short arrow), then before I get to turn the light changes. Why can't the same technology ensure that the arrow doesn't go away until the last car turns?