Ramp meters have been around for a while, but only in a few limited ares. I live in Milwaukee, WI, which is one of the places that use them.
I’m looking to set a standard for mapping these, but wanted to open up the discussion to the US and get some more input before trying to get it written into the wiki (either State or National level).
The purpose of the junction would then be to collect accurate speed data before and after the light to help with navigation, especially during rush hour.
The purpose of removing the name on the remainder of the ramp is to help protect that junction from being deleted by any of the automatic scripts, or even an editor that doesn’t know why it’s there. (since the two segments aren’t named the same, it shouldn’t allow you to delete the junction or merge/bridge the segments)
I am not aware of any metered ramps in Idaho, but I’ve encountered some in Utah before. I can see your reasoning behind it. I cannot think of any problems that would occur from implementing this in this way. I’d be good with it.
EDIT:
As I think about it more, and consider @tonestertm’s response, I think I answered too quickly. Waze will monitor the speeds of the ramp as a whole in its determination of whether the ramp is a good route or not. During times of metering, the ramp as a whole will be slower. If metering is off, the ramp traffic will move faster.
It does not seem it would improve routing to junction it. It would give Waze speed/traffic data for how long a merge takes after having been metered, but I don’t know if that is data they really need for anything.
Almost all of our ramps are metered here. There’s no need to add a junction or to do anything special. The time of waiting at the light is included in the time of transit for the ramp (complex). Just make sure the onramp junctions at the proper merge point on the freeway, where people are actually able to join the traffic flow, if there is a slow merge. We have one particular spot where, during rush, people don’t merge until the very last point they possibly can. This needs to be included in the ramp time, otherwise the ramp looks faster than it should be.
Are you having any problems with routing? I don’t see any with the ramp meters in the Northern Virginia/DC/Baltimore area.
To me it is basically a stop light that occasionally is on. Similar to when a small town turns off a stop light at night and goes to a flashing yellow on the primary street and flashing red on the secondary street.
The speed history portion of the algorithm should take care of it automatically. I would think that the junction that you add is unnecessary. There is a list of why to have a junction between two straight segments and this is not one of those reasons. I know that Speed Limits needs to be added to that list and I submitted that change a while ago and it is in process.
No problems, that I can see. My thought was that if congestion on a ramp was better tracked, it would help to route drivers away from those ramps and onto the highways at different locations.
As Tony mentioned, Waze is looking at the total transit time from start to finish of the segment. Which should be enough to show the congestion and initiate a re-route if warranted.
I’m on the fence here. On one hand, I can’t really refute tonestertm’s logic. On the other hand, if is the complete truth, then I don’t understand why we are junctioning railroad segments to the road network.
Quite awhile ago when there were still many complaints about “Are you in traffic” prompts when sitting at traffic lights, some staff member told us that waze filters out the slowest 50 meters of a segment for traffic detection purposes. (There has been a lot that has changed since then.) There was thus talk about breaking segments when the slowest 50 meters was not at the end of a segment. Thus there were proposals to add the node as you suggest, so that you would not get a “Are you in traffic” prompt at the traffic meter light. But if I recall correctly, the general consensus was not to do this. I don’t remember the details, but maybe we thought that traffic meter lights might be an acceptable place to be given an “Are you in traffic” prompt.
I have no empirical evidence to support this claim, but anecdotally: I’ve never been asked “Are you in traffic” on any ramp-typed road segment. Maybe the entire road type has the prompt disabled?