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Virginia currently uses smart traffic signals: > Traffic-responsive signals vary the timing of the lights according to the amount of traffic. They use sensors
by 3minus1 12y ago
Virginia currently uses smart traffic signals:
> Traffic-responsive signals vary the timing
of the lights according to the amount of
traffic. They use sensors to detect the
number of vehicles on an approach. The
time the light stays green adjusts to let as
many drivers as possible through before
the signal changes to respond to traffic
coming from another direction.
Back when I lived in NoVa, the lights near me had this and it was awesome
- WalterBright 12y agoLots of lights have inductive loops to detect cars, but they are too close to the lights. The cars have already stopped by the time the loop detects them. How does the Virginia system detect the cars?
- count 12y agoThe VA system detects how many cars are waiting to ensure that as many as possible make it through in a cycle (up to a limit), not detecting them as they are inbound to keep the light green.
- WalterBright 12y agoThat's a familiar system, but it requires a car to come to nearly a full stop before the sensor picks it up. This leads often to the lights alternating so out of phase it produces the maximum delay for both streets.