Thailand/uturns

o  1.1 Dedicated U-Turn Lane Construction

o  1.2  Short U-Turn Construction

o  1.3 Dedicated U-Turn Lane Construction with Side street Connection

U-Turn Constructions

1.1 Dedicated U-Turn Lane Construction

Concept: dedicated U-Turn lanes on a divided road.

The following guidance applies only to dedicated U-Turn lanes that allow traffic to turn around to access addresses on the opposite side of a divided road.

Concept: use a segment of the same road type as the connecting type, streetname “U-Turn” with cityname (when known), connected with a small departure angle of 22 - 44 degrees to trigger the "keep right to U-Turn" instruction then connected to the opposite side at a 90-degree angle.

Click here for a live example of an “Dedicated U-Turn Lane”: https://www.waze.com/editor?env=row&lon=100.67416&lat=13.71956&zoom=8

Notes:

1- U-Turn departure segment should start just before the beginning of the solid white line (point of no return) for the dedicated U-Turn lane.

2- The 90 degree connected segment should have a TIO to indicate “U-Turn” instead of the standard “turn right” instruction.

3- The U-Turn segment needs to be of the same elevation as the road it is on.

4- After construction set the Lock Level to the same level as the road classification, or minimum L3.

To ensure proper construction and angles, it is essential that you have the Junction Angle Info tool installed before attempting to create a U-turn construction.

1.2 Short U-Turn Construction

This construction is used where there is no dedicated U-Turn lane to connect a divided road yet U-Turns are allowed.   A segment should be added to connect the two divided roads at 90 degree angles with the total length of the U-Turn segment at least 16 meters to ensure proper navigation. The segment should be the same type as the main roads that it is connected to and should be named “U-Turn” (unless it is also connected to a side road for right turns, in which case the segment will not be named but will include the city and state, if known).  The U-Turn segment should be locked at the same level as the road it connects, or at least L3.

Click here for a live example of a “Short U-Turn”: https://www.waze.com/editor?env=row&lon=100.59452&lat=13.67556&zoom=9&segments=370704089

A TIO for “keep right” should be placed on the first turn to the U-Turn and a TIO for “u-turn” should be placed on the last turn.  This will provide the drivers with the same navigation commands as an extended U-Turn and will help ensure they are in the right-most lane in advance of the U-Turn.  For example, the TTS instructions heard by the driver will be “in 300 meters keep right to U-Turn, then U-Turn”.

1.3 Dedicated U-Turn Lane Construction with side road

This construction is the same as a normal “Dedicated U-Turn Lane” construction, except the segment remains unnamed, except for the city and state (if known).

A TIO for “u-turn” should be added for the turn connected to the opposite side.

A TIO for “turn right” should be added to the connected side road.

The segment connecting the side road to the opposite side of the divided road, in most cases should be a one-way segment and should be the same road type as the side road and locked at the same level. 

Click here for a live example of a “Dedicated U-Turn Lane Construction with side road”: https://www.waze.com/editor?env=row&lon=101.15109&lat=14.22113&zoom=8