left turn signal

[liu]

I noticed most intersections have multiple cameras on the top of the lights. I wonder does it detects the cars in the left turn lane. I noticed sometimes that if there is no car in the left turn lane, the left turn light would be skipped directly to show only the green light for straight line traffic.

Someone told me that if you don't turn on the left turn signal, you would get ignored and not given the left-turn green light.

Does anyone know if it's the case and whether traffic lights are smart enough to detect the needs for left turn signal?

Thanks,

[Jeff]

Post by liu
I noticed most intersections have multiple cameras on the top of the
lights. I wonder does it detects the cars in the left turn lane. I
noticed sometimes that if there is no car in the left turn lane, the
left turn light would be skipped directly to show only the green light
for straight line traffic.
Someone told me that if you don't turn on the left turn signal, you
would get ignored and not given the left-turn green light.
Does anyone know if it's the case and whether traffic lights are smart
enough to detect the needs for left turn signal?
Thanks,

Around here they use sensors in the pavement to detect cars in the left turn
lane. Sometimes they are programmed to turn on the turn arrow on alternate
cycles in case a vehicle is there that was not detected.

Some places use cameras on the lights to detect the flashing lights of
emergency vehicles to stop the traffic and let them pass.

[t***@gmail.com]

I have either bad luck or terrible timing
when it comes to getting a left arrow in
the protected left turn lane! I even sat
through most of a full red cycle(all lanes)
and still got only full green - all lanes!
(And yes, I do pull nose right up to the
stop line)

Unless my 'aura' is somehow affecting
protected left function at multilane
intersections.