MnGCA

msrubble · Posted: Sat Dec 30, 2006 11:21 pm Post subject: Divided Highways

Another newbie question: if the mark is near a divided highway, with a median strip, is the measurement taken from the centerline of the nearest lane (or set of lanes), or from the centerline of the entire highway?

For example, I think I know where to look for QP0063, 7305 A. I have spotted what looks like a MnDOT witness post near a large rock in about the right area. Highway 23 at this point is two lanes in each direction, with a median strip in between. If I can find the mark, I would like to update the description.

EskoClimber · Posted: Sun Dec 31, 2006 1:19 pm Post subject:

I've read the description a couple of times and I'm not sure. From the looks of it I would look for the rock outcropping and search from there.
The other thing is that I don't think the NGS will accept description updates from geocachers. They will accept description updates from surveyors since they've been trained.

Pear Head · Posted: Sun Dec 31, 2006 2:03 pm Post subject:

msrubble · Posted: Sun Dec 31, 2006 2:05 pm Post subject:

Pear Head · Posted: Sun Dec 31, 2006 2:20 pm Post subject: Re: Divided Highways

EskoClimber · Posted: Sun Dec 31, 2006 10:27 pm Post subject:

I've only tried to update one description which explains my statement.
Pear Head is right about the mark. Make sure its there and make sure the stamping is exactly as stated in the description. A lot of marks get reset and the only difference is an added date.
A reset marker would also explain why the description fails to note which set of lanes is referenced.
I just checked to see if NGS had any new markers around QP0063 that gc.com didn't but there isn't anything listed. My guess is that if you can see the witness post you should be able to find the mark.
Good luck.

msrubble · Posted: Mon Jan 01, 2007 12:10 pm Post subject:

I have only driven by, not stopped. This stretch of highway has several rock outcroppings.

The two closest marks in the gc database are on the north side of the road; this one is on the south.

Sure, it could be a reset, or it might be a MnDOT mark that's not in the NGS database.

In any event, this still does not answer my question. Measurements are from the center. What is the center in the case of a divided highway?

EskoClimber · Posted: Mon Jan 01, 2007 3:35 pm Post subject:

Sorry about that. In this case I have no idea.
Every mark that I've seen referenced to a multi lane highway says which set of lanes to use (northbound for ex.). The times where there wasn't a reference was because the mark was set when the highway was a two or an undivided 4 lane. The road was since updated but the descriptions wasn't.
I'd start looking south of the road from the way the description reads.

fidian · Geocacher Joined: 23 Nov 2005 Posts: 126

If you are talking about mile markers on divided highways, I know how the mileage is figured. On non-divided highways, it is based on the centerline. On divided highways, the mileage numbers used is for the "centerline" of the road on the outside of a curve. So, if you have an S shape, and you are driving from the bottom to the top, the mileage counted towards the mile markers is first from your lane until you get to the straight part, then they count the outside lane.

However, this is all fudged if they need to redo a road, and you can get mile markers placed somewhat arbitrarily at times.
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