Junctions and Traffic Lights

Where two roads meet, a junction appears. From three sides on it gets traffic lights. They control the traffic all by themselves, there is nothing for you to set.

How a junction appears

Drag a new road across an existing one. The preview then asks what should be built there:

• Junction: both roads meet at the same level, with traffic lights
• Bridge: the new road crosses over without an exit (Bridges)
• Roundabout: a ring instead of lights (Roundabout)

If a road ends at another one, you get a T junction with three sides. It gets traffic lights too.

The traffic lights

Every junction plans its own lights:

• Crossing directions never get green at the same time. Between the phases there is yellow and a short pause in which everyone has red.
• The busier direction gets more green.
• Junctions in a row on the same road switch like a green wave.
• If someone is waiting across and the green side is empty, the light switches sooner.
• A new plan only starts with the next cycle. No signal ever jumps without yellow.

How cars drive

• Lining up: Shortly before the junction cars move into the right lane. Right turns to the far right, left turns to the inside, straight ahead in the middle. Nobody changes lanes inside the junction.
• Left turns wait at green for a gap in the oncoming traffic.
• Don't block the box: If there is no room behind the junction, nobody drives in, not even at green.
• Nobody waits forever: If nothing at all moves in a junction for a long time, the car that has waited longest may go first.

At the highway

There are no signalized junctions at the highway. If a road crosses or reaches the highway, a cloverleaf interchange appears on its own (Highway Interchange).

Frequently asked questions