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Re: [Page Update] Limited Access Interchange Style Guide

Mon Apr 14, 2014 6:50 pm

I like the MUTCD example. If you want a permalink, I think the I-270/I-495 split is here. Not sure why the "Exit 17," as its been decades since the Washington Beltway exits were numbered consecutively rather than by milepost.

Re: [Page Update] Limited Access Interchange Style Guide

Fri Apr 18, 2014 11:12 am

Well, the simplest method is simply to leave city names off all freeway segments which really doesn't affect the city layer either. This results in reports that say near the city rather than in the city which seems more appropriate to me for the vast majority of city names. You don't really think you're "in" the city when on the freeway around here, with the exception of the biggest major cities. Thus, the only city name that is on freeway segments in Maryland is "Baltimore" as it does seem odd to get reports that say "near Baltimore" when you're clearly in the city.

Re: [Page Update] Limited Access Interchange Style Guide

Fri Apr 18, 2014 2:29 pm

The one thing I didn't mention is that state borders have the same effect as city borders. So all the options that Kent mentions are also applicable to interchanges where the state changes.

Re: [Page Update] Limited Access Interchange Style Guide

Fri Apr 18, 2014 3:31 pm

Well, the freeways don't have city names around here. I didn't think they had any use at all until some complained about reports "near Baltimore" when you are essentially downtown. So the renaming project in my area would be putting city names on freeways.

But I agree that we never know whats best as the things are always changing. I'm not entirely accurate that no names are on the freeways here. There have been some that have names added to avoid reports near phantom cities. But I think we have the phantom city problem under control. So we'll likely leave the city name off around here.

Re: [Page Update] Limited Access Interchange Style Guide

Fri Apr 18, 2014 4:42 pm

daknife wrote:And in some states, rural or not you are always within incorporated boundaries (PA).

Well as I've said before I don't find the township boundaries in Pennsylvania to be terribly helpful for orienting myself when navigating. I grew up in London Grove Township, but London Grove is no longer in London Grove Township (just like Chester is no longer in Chester County). So you only see the London Grove exit sign where you would get "Car stopped on shoulder in New Garden" not where you would actually get a "Car stopped on shoulder in London Grove" message. It would be a much larger project to tag all segments in PA with their township names than it would to remove city names from the freeways.

kentsmith9 wrote:Seems like we are proposing the following change to the Wiki (at least for the USA):

  1. Stop adding city names to freeways . . . when not already present.
  2. Remove city names from these same roadways around interchanges if the city name changes on either side.

With regard to major/minor highways, I have always assumed the that the benefit of having a city name for routing to addresses or places along major or minor highways would outweigh any advantage to not having the cityname.
kentsmith9 wrote:Question: Should we review with Waze staff just to be sure there is nothing we are missing or they have never told us, or that they possibly will be doing something in the future with the city names on these roadways?

I'm always for attempting to get more information from Waze staff.

Re: [Page Update] Limited Access Interchange Style Guide

Fri May 09, 2014 6:04 pm

There seems to be an unfinished thought here:
OUT segments should be named with the information displayed on the roadway signs. However, if this would leave

I would change:
Do not use "to" in the name of the continuation segment - the user is already on the road, not going "to" it.

to read:
Do not use "to" to start the name of the continuation segment - the user is already on the road, not going "to" it.

If the BGS has "to" on it then I'd include in the name of the continuation segment.

Re: [Page Update] Limited Access Interchange Style Guide

Fri May 09, 2014 6:46 pm

sketch wrote:I'm not sure what guidance we should recommend here specifically though — Do we impute a control city that isn't on the sign? Do we leave a direction out? I've seen a wayfinder somewhere in Ohio or Michigan that's just signed with the I-75 shield, so I left the "N" off it since it doesn't actually say "North" on the sign. I also put a wayfinder named "Elysian Fields" on Elysian Fields Ave because the BGS does say "Elysian Fields" without a suffix. I don't know that I'd recommend that necessarily if the sign does include a direction, though.

In those circumstances, I've put a short no name segment before the split to serve as the IN segment. That breaks the name continuity and allows an instruction for just "I-75 N."

Re: [Broken Link] Limited Access Interchange Style Guide

Sat Mar 29, 2014 2:18 am

Btw not sure where it should be placed, but I'm thinking with interchanges. It would be adviseable to add Diverging Diamond Interchanges to the selection. These are not difficult to map correctly but can be confusing to draw in if the editor doesn't fully understand how they work. I can provide a links to a couple such interchanges to use as examples.

1st: A good overhead view one where the DDI is on top. American Fork DDI
2nd: A more compact one fit in under an existing highway overpass. Lehi DDI

I don't know about other states but Utah's DOT is in love with these, and rightfully so. They are very efficient and safe, even better than SPUI's because nobody turns across the flow of traffic. They look confusing but are a breeze to drive and they handle large volumes of traffic very easily. We have five in the state currently and several more already on the way.

Plus feel free to ID me as an expert, I've mapped in every DDI in the state to date. And am always willing to help someone map one in, or do it for them.

Re: [Broken Link] Limited Access Interchange Style Guide

Sat Mar 29, 2014 2:03 pm

Because if you don't split it, you get bad turn instructions. As I said, I've mapped all five of the existing ones in Utah and tried to figure out a non split method, it does not work. I tried it. With the way the traffic crosses over. You have to have split lanes, turn restrictions alone (remember they are only penalties, not absolute) are not sufficient to ensure proper routing and correct instructions.

Tapatalking via my Galaxy S4

Re: [Broken Link] Limited Access Interchange Style Guide

Sun Mar 30, 2014 5:59 am

Okay, honestly it's been nearly three years since I started playing with these interchanges. I don't recall the exact errors. All I can really recall is that it simply works with a split, and it was throwing errors without. I'm trying to recall (I even just drew and then deleted one in the middle of nowhere to try to remember) And maybe it wasn't so much as bad turn instructions as it was much more confusing to draw in correctly without the split.

Compare: FIrst the Lehi DDI CBenson mentioned specifically. Let me show it with and without the satellite imagery.
Lehi DDI w SAT.jpg
(95.3 KiB) Downloaded 581 times

Lehi DDI no sat.jpg
(117.83 KiB) Downloaded 584 times

Now compare with a single lane DDI I mapped out in the desert. This was done rather hastily and would be tweaked a quite a bit but is mostly accurate to ramp placement necessary for proper function of the DDI.
Single Lane DDI.jpg
(75.13 KiB) Downloaded 592 times

With the Split, it is clear where each ramp segment needs to connect, to match the cross-over, You also ensure that the left turn ramps onto the freeway starts sufficiently early, (hate it when some driver tries to jump three lanes left at the last second because they didn't realize how it worked) Without the split working often months before you get updated aerial imagery, you are left guessing as to correct placement, is your node placed before the cross-over or after?

The more I think about it, I am probably totally wrong in my prior claim that it was giving bad turn instructions though I still think there were a couple such UR's but those may have been more due to angle of connection factors. But rather I now seem to recall that it was just confusing as hell to try to map out correctly without accurate imagery. Whereas with the split, it is far easier to visualize where the cross-over is and place your junctions appropriately. If your state tries one of these please try a single lane. Maybe you can get it to work. But the split is easier to map. And (not that this is a critical factor) it looks far more elegant than the jumble of crossing ramps.

As the board system only allows three attachments I will follow this post with one more example, where it goes single to split and back to single and comes off looking very elegant as well as navigating correctly. As with the Lehi example this one was built withing the pre-existing space of a prior interchange so it is more compressed space wise than the American Fork example I lead off with in my original linked examples. That interchange was entirely redesigned and rebuilt to meet the new Pioneer crossing road to the west.
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