Doubled up interstate?

Posted by Mythdraug on 26 August 2009 in English (English).

First, I'm relatively new and only edit in potlatch.

While adding relationship status to US:I-80 near the junction with US:I-99 ( I came across an arrangement I was unable to resolve.

I added the relation to one direction and scrolled to the end of the way. The next way on the carriageway did not have oneway, so I added it. When I did so, i got duplicate direction arrows on the way I had just added the relation to. Looking closer, I realized that I had two ways sharing nodes both representing one direction of interstate for that area.

When I attempted to delete the nodes of one of the ways, both were affected.

I-80 WB way 1:11844889
I-80 WB way 2:34932489

This carries across multiple counties and multiple way sections of I-80 in both directions.

Advise and recommendations greatly appreciated.


Location: Marion Township, Centre County, Pennsylvania, United States

Comment from Milliams on 26 August 2009 at 20:16

This is a problem which has been known to occur from time to time. Currently the easiest way to fix it is with Merkaartor or JOSM since both provide greater control over your selection stack. I'd suggest you try fixing it with one of those or ask someone else to do it at a time when you're not editing those same ways (t avoid edit conflicts). Basically, you need to delete one of the ways.

Comment from Sven L on 26 August 2009 at 22:38

Hi Mythdraug,

These duplicate ways are an artifact of a double import of the TIGER data in several counties, mainly in Pennsylvania (see Unfortunately, it's not limited to the I-80 but affects every single way segment in these counties… I've been editing a lot in this area so I know all about the trouble you're running into. If you feel uncomfortable deleting one of the ways, I can do it for you.


Comment from RussNelson on 28 August 2009 at 21:04

If you're seeing the same thing that I saw on I-87 in New York State, then what's happened is the way has been wrapped around on itself. My solution was to split the way at the very end node where it wraps around, then figure out which copy of the way is shorter (it wasn't completely wrapped back), and delete it.

Comment from RussNelson on 29 August 2009 at 04:26

I looked at it. Yes, it's just as Sven L said -- that entire county was double-imported. It's tedious to fix by hand. I'd hope that somebody already has a program to look for duplicates and delete them.

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