Hello, neighbors. I’d like to see whether there is a local consensus on restricting turns that are technically legal but potentially unsafe.
There are currently two open URs here and here complaining about Waze recommending left turns onto Arlington Boulevard (US 50). For those who don’t know the area, US 50 is a heavily-traveled, six-lane major highway with a mix of at-grade and grade-separated intersections. There are traffic lights at Irving Street and Fillmore Street. In between, there are unsignalized intersections with four residential side streets. Amazingly, there are no restrictions on left turns or straight-through traffic from the side streets at any of these intersections. And, if you are driving between 2:00 and 5:00 AM on any given day of the week, you might be able to make one of those left turns safely. 
During most of the day, however, traffic on US 50 is heavy and it would be foolhardy to try to cross the six lanes either straight-through or to make a left turn.
Would it make sense to restrict these intersections in Waze to allow only right-turns from the side streets onto Arlington Blvd, and to disallow left turns off of Arlington Blvd onto the side streets, even though these movements are legal? I personally agree with the drivers who posted the URs that it is dangerous to recommend these turns even if they are legal, but I’d like to see what others think.
There is also a somewhat similar case here near the interchange of US 50 and Washington Blvd; there is no sign prohibiting a U-turn on Washington Blvd, but trying to come off the US 50 ramp and then make a U-turn during rush hour would be practically insane. Currently that U-turn is restricted, but I have seen it go back and forth over the past few months, and it always generates URs when it is allowed.
In any case, Arlington Blvd is locked at level 5, so it will take a CM to implement any changes there.
Since we don’t have time based turn restrictions, the best we can do is pick a choice that is technically accurate even if it results in people getting directed to take a left across 6 lanes of rush hour traffic. What should happen is that the map will learn that it’s faster to wait for a stop light down the street then to sit during rush hour waiting to make a left, but I’m not sure they check the direction of your turn when they calculate the travel times for segments.
For the Washington Blvd intersection, you can extend the ramp to the intersection to disable the U-turn for only ramp traffic, but I wouldn’t do that if it’s legal to make a U-turn there. Since automated UR’s appear any time a few people make turns through a restricted intersection, we’re just setting ourselves up for more problems if we try to regulate directions this way.
Typically I prefer to leave the legal turns enabled and let waze learn how slow they are. Once waze knows how slow they are, waze should choose alternate more practical routes. Of course if no one ever takes the proposed routes, waze will never learn. So I will usually take the waze suggested route through near impossible turns like these. After I do this a few times, waze stops routing through them.
However, your examples are quite extreme. I’m not sure I’d actually have the fortitude to take the abuse one would receive while waiting to try make the left from Arlington to Garfield during rush hour. I could see waiting to make the left from Hudson onto Arlington as you wouldn’t be blocking anyone else, but that could be a really long wait. But I’m not sure I’d even attempt the left from Garfield or Highland to Arlington with the hillcrest so close. If I’m unwilling to take the turns to provide waze the information needed to learn that these routes shouldn’t be taken, then I’m willing to restrict them on practicality/safety grounds even if they are legal.
My experience commuting in the area was primarily on Columbia Pike and was over a decade ago. But I can still sympathize with the wazer’s leaving the URs.
I knew exactly what area you meant without even looking at the links. I drove in on Rt 50 recently, and was like, “WTF?!?” How the hell am I supposed to turn here. No turn lane and tons of traffic. BUT I still say leave it open and let waze learn. I drove past the left turn and waze told me the next logical left which has a turn lane.
The only time I think disabling the turn is better is if Waze just isn’t learning, for example sometimes it insists on taking two left turns around a triangle instead of the hypoteneuse and never learns. There was one case (in my area) where I finally just disabled a turn because it was so dangerous.
Rebumping this. Saw a UR about waze routing them OVER 50. Completely unsafe but technically valid.
Should we restrict crossings to only lights?
Example (please leave UR open for now):
https://www.waze.com/editor/?zoom=6&lat=38.87327&lon=-77.09203&layers=BFTFFTTTTFTTTTTTTTTTTTTFT&segments=62280957
I don’t really see turning left from Highland any different from cross 50 on Highland. Is the maneuver really not allowed?
No, the maneuver really is allowed; it would just be insane to try it during normal daytime traffic conditions.
And even more insane trying to cross 50. It’s 6 lanes here. And yes it’s technically legal.
I understand Waze probably took waiting at the light into the route calculation and assumed crossing here was “faster” because I’m sure few people have attempted to.