Junctions with bridges, no longer needs any traffic light

1. The price is extra lanes and then merging of lanes.
2. Even I made the mistake of requiring underground tunnels at the U-turns that still require mergings. In fact, you do not need to provide a tunnel or bridge to do the crossing. Just provide a U-turn into the lane, without crossing the road.
3. The U-turn needs room, so extra lanes are required at the turning areas. U-turns will take up 2 extra lanes, so the straight roads need to be provided with 2 extra lanes altogether.
4. At Kota Kinabalu, U-turns are already provided with 2 extra lanes but a traffic light is still required.
5. Let the lanes going to the junction be curved so that vehicles need to slow down. Vehicles making U-turns need to cross lanes to turn left, effectively making a right-turn from the junction.

KK UTURN

U-TURN