AlanOfTheBerg wrote:With more Wazers and more accurate traffic data, Waze is likely getting "better" at not doing this routing, but the fact remains that the code still allows it, even with no traffic impact, and that only makes it more likely to be routed like this when traffic on the freeway is backed up. This ramp-to-ramp route is illegal in many states, just like using parking lots to bypass traffic on a surface street.
Someone in this thread asked how to 'reproduce the off and on' ramp issue, and I think I know of a good way to do it, because I've found a total of two off-and-ons exactly this way.
So I start in say, SeaTac, WA with my Waze client in hand. I tell it to navigate to Centralia, WA. The logical route for this is I-5 S.
It'll compute a route. USUALLY the first time, this is a sane, straight through on I-5 route down to there. Here's where it gets interesting.
If I tell it to calculate alternate routes with the route button, it'll often come up with something else that looks ALMOST identical but isn't. And specifically, what it usually finds is an off and on, sometimes on a diamond, sometimes on a cloverleaf slip road. I already found one of these on exit 120 (Fort Jones, fixed with a slip lane crossover that allows a cloverleaf U-turn but not the I-5 off-and- on), and when I did the alternate route test again, found another
at 132A (which I haven't touched, and in any case I'm satisfied of what I'm saying). I was doing this at 2 AM local time, so traffic ain't the issue.
I would conclude that at least at the present time, it IS in our interest to prevent off-and-ons with segment building or hard turn restrictions wherever possible, because the routing engine isn't looking deeper than off-and-ons for alternates as it is now - I just demonstrated it. The routing server only has so many cycles, and it testing whether off and ons are faster is kind of a waste, right? Thoughts?
EDIT: Oh, and...if you look at exit 132A (Permalink: https://www.waze.com/editor/?zoom=3&lat ... TTTFTTTTFT
), all roads in this area having to do with the exit are in the city of 'Tacoma'. No changes to and from one city to another. So it's still trying the off and on even if the cities are the same throughout.)