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Lesson 2 of 8

AI on the road

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8 min

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A signal stays green for an empty road. A long line waits on the other. Can it do better?

A fixed timer gives each road 30 seconds.
Step 1 of 4
  1. A fixed timer gives each road 30 seconds.
  2. Road A has 2 cars. Road B has 12.
  3. Cameras can count the cars.
  4. A made-up rule gives A 16 s and B 44 s.

Yes, it can give more green to the road with more cars.

A made-up rule is one invented for this lesson. Here, s means seconds. The sign ≈ means about equal.

The made-up rule has 60 s in all. Each road gets 10 s. The other 40 s are shared by the cars waiting.

  • Cars waiting: 2 + 12 = 14.
  • Road A: 10 + 40 × 2 ÷ 14 ≈ 16 s.
  • Road B: 10 + 40 × 12 ÷ 14 ≈ 44 s.

A signal that changes its timing with the traffic is called adaptive. Some cities already use such signals.

Navigation apps use live traffic and past traffic to suggest a route. Live traffic means traffic as it is now. A fully self-driving car needs no driver. Fully self-driving cars still work in limited places.

Cameras can count the traffic. A program can change the green times to match.

Slide the cars on each road. Meet each task.

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