Signal Swap

A traffic-light game with ten difficulty steps: tap to switch which road gets green and get every car through the crossing without a crash or a jam. The traffic changes every day.

Controls

Tap the screen, click, or press Space

Time limit

45 seconds

Score

Clear time, lower is better

Type

Strategy

How to play Signal Swap

1. Two roads meet at a crossing with one set of lights. Only one road has green at a time.
2. Tap anywhere to switch the green to the other road.
3. A car that’s already past its stop line keeps going. Switch while one is still crossing and the other road’s cars hit it.
4. Cars stop and queue at a red light. On difficulty 5, four waiting on one road is a jam and the run ends; get twenty cars through to clear it.
5. You start on difficulty 3 of 10. Clear a difficulty to unlock the next: more cars, coming closer together and a little faster. Pick any unlocked difficulty with the arrows on the start card.
6. Each road gets a rush hour, one after the other.

Tips

• Switch when the crossing is empty, not when a car is halfway over.
• Give the busy road long greens, but don’t forget the other queue.
• The “waiting” count by each road warns you before a jam.
• Everyone gets the same traffic all day, and new traffic at midnight UTC. “Practice a new layout” deals a fresh one any time, off the leaderboard.