U-Turns
Waze allows U-turns at junction nodes or over a series of segments. U-turns at junction nodes are often barely possible if at all and drivers generally dislike them. The standard in Canada is to never enable the U-turn at nodes. Unlike US editing practice, this rule also applies to parking-lot roads in Canada.
Waze can recognize U-turns ove a series of segments at H or # style intersections on divided and parallel roads, like these:
Waze will recognize such a turn when all three of these conditions are met:
- Three segments - The U-turn is a reversal of driving direction through three segments: an incoming segment (A), a single median/crossing segment (B), and an outgoing segment (C).
- Short median - The median segment (B) is less than 15.0 metres long. Note that the WME rounds decimal places to the closest integer. A segment that is 14.8 metres long and a segment that is 15.4 metres long will both appear to be 15 metres long in the WME although they will behave differently in U-turn recognition. Always adjust such median segments to 14 metres and less or 16 metres and more to trigger the U-turn behaviour you desire.
- Parallel segments in and out - The in and out segments (A and C) are within ±5° of parallel to each other. The sum of the angles through the U-turn must measure between 175º and 185º .
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It is possible for this method to fail to recognize a U-turn when it is the first segment of a route or it immediately follows a reroute. |
The default condition in Canada is to have the Waze routing algorithm prevent U-turns through median segments 15.0 metres (or less) long. The US allows them. The rationale for this decision is that most standard vehicles have a turn radius of 10-15 metres, making such U-turns difficult in all but perfect conditions.
How to prevent U-turns
The best way to prevent a U-turn through a junction that would permit it by geometry is with a junction box (an editor rank of 4 or above is required to install a junction box).
If you can establish all required prevention of U-turns with that junction's standard turn restrictions, use those to prevent a U-turn. This situation is most commonly found at three-way intersections.
The only other way to prevent U-turn routing through a geometry that would permit it is to artificially narrow the median segments to less than 15 metres. This used to be the preferred method but is now obsolete.
How to enable U-turns
Sometimes you have a geometry that by default would not allow a U-turn in Waze but it is important to allow one for user navigation. One example is a destination on the other side of a divided road that would otherwise require an excessive detour to get to.
Again, the easiest way to enable a U-turn through a geometry that would prevent it is with a junction box. Junction boxes overrule all default conditions inside them.
The other way to enable a U-turn through a median segment that measures less than 15 metres is to create a node on it, but we do not recommend this. Nor do we recommend artificially widening a junction to create a median segment larger than 15.0 metres.
Where to enable U-turns
Every province maintains its own road code. In Quebec, for example, you can make a U-turn at any intersection unless it is forbidden by a sign or you must cross a solid lane marker line to do so.
Despite provincial regulations, we generally discourage U-turns because they provide a poor experience for the Waze user. Use your discretion in accordance with local regulations.
Here are the provincial regulations we have found. It is important to note that some municipalities have their own U-turn restrictions. For example, Saskatoon has rules that are not aligned with provincial regulations.
British Columbia References - Motor Vehicle Act of British Columbia Chapter 318 - Section 168
Alberta References - Use of Highway and rules of the road regulation - Alberta Regulation 304/2002 - Division 7 Pages 28-31
Saskatchewan References - Saskatchewan Driver's Handbook
Manitoba References - C.C.S.M. c. H60 The Highway Traffic Act: Section 191
Ontario References - R.S.O. 1990, c. H.8, s. 143. Highway Traffic Act
Quebec References - The Highway Safety Code does not specifically mention U-turns, so they are allowed at any intersection unless expressly forbidden by signs or other restrictions such as crossing solid lines.
New Brunswick References - New Brunswick Highway Act - Section 162(1)
Prince Edward Island References - PEI Highway Safety Act - Section 182
Nova Scotia References - Nova Scotia Highway Act - Section 158
Newfoundland and Labrador Statute - RSNL1990 Chapter H-3: Highway Traffic Act, s116