OpenStreetMap

A JOSM screenshot of the road network for Rifle Colorado

The problem with remote TIGER review (and solution!)

I recently did a major road alignment update for Rifle, Colorado. With JOSM and the to-do plugin, it only took a few hours and the road data is much improved. Doing the geometry check was time consuming but easy. Checking that the names are all correct? Isn’t that impossible from my desk? Thankfully no!

There are two kinds of name checking that I like to do. The first is to check that they are “sensible”, meaning that they have been expanded and there’s no obvious vandalism. The next is that they are “correct”. Because most road names originated from the TIGER import we shouldn’t use it to cross check for “correctness”. The good news is that the National Address Database has data for huge chunks of the country and provides us with another source to get a sense of how good the road network is named.

The workflow

Requirements: JOSM, the MapWithAI plugin, and an area that has NAD data available. I also recommend the AddressValidator paint style.

  1. Download an area you want to do review
  2. Work through the geometry updates however you wish
  3. Use the MWAI plugin to pull down the set of address data for your area.
  4. Merge nodes into the OSM layer
  5. Run the validator.
  6. Review the MWAI “Addresses are not nearby a matching road” warnings.
  7. Delete any unreviewed MWAI data. (Find and delete: type:node AND new AND "addr:housenumber")

If you’d like to keep the addresses, good news!, I’ve written diary entry about working through that data.

Some common errors caught this way

Usually the roadway names match very well so this isn’t a totally onerous task. However, there’s a few classes of errors that seems pretty common:

  1. A typo in the road name (ex: a road name that is close to a different common word and been manually entered incorrectly)
  2. Unexpanded road name (ex: E Diary Entry St -> East Diary Entry Street)
  3. A road that needs to be split because it actually changes names but isn’t reflected in OSM (most commonly a user extending an existing road without knowing)
  4. Missing/wrong directionality or quadrant (ex: 103 Street -> East 103 Street)

Of those, the 4th one seems somewhat optional if the rest of the roads locally do not have directionality markers. For my local area, I updated directionality but there’s some disagreement about what’s “correct”. Up to you.

Comment from SherbetS on 24 January 2023 at 22:59

Excellent work! I’ve never considered using the NAD for this purpose.

I could see this being helpful for Florida editors where the TIGER overlay has a serious prefix addiction (counties will have nearly every road labeled with a directional prefix such as southeast regardless of ground truth)

Has you found errors in the NAD street name from doing this?

–SherbetS

Comment from watmildon on 25 January 2023 at 00:49

When I did the Indianapolis import I definitely hit issues where they disagreed. In those cases I had to find ANOTHER source of data to tie break, typically street side data. You can also see notes I left around Indianapolis like “what is the name of this street ‘foo’ or ‘bar’?”. Because I figured it would eventually get seen by a local and they can help be my arbiter.


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