Exit and Destination Signs project

[skudrashou]

Summary

In an effort to improve the navigability in cities across North America, the Lyft OSM Data Curation Team is undertaking efforts to update missing key road features that include exit numbers, destination areas, lane count, and turn lanes. The missing features are identified algorithmically and validated using various sources of ground truth info (please see below)

Project documentation

Destination Lyft Policy

Features Mapped

Node

• highway=motorway_junction
• ref=*
• noref=yes

Linkway

• highway=*_link
• oneway=yes
• oneway=no
• junction:ref=*
• destination=*
• destination:street=*
• destination:street:to=*
• destination:ref=*
• destination:ref:to=*

Quality Control

To keep the quality of our map edits at a high level of accuracy, we apply a quality control (QC) process on 100% of tasks. Each task will be QCed before being published to OSM. Our QCers are checking key tags on the Node and Linkway. If the curator accidentally added wrong or unnecessary features, the task will be returned to the curator to correct it based on the QCer’s comment.

Ground Truth Resources*

• Street level imagery (Bing, Mapillary)
• Aerial imagery (Bing, Nearmap)
• Lyft owned sources (ex.proprietary) of aerial and street level imagery

OSM changesets will be submitted abiding by the OSM Changeset Guidelines.
*Additional resources used in curating and QCing this project can be found in our Resources Wiki

[1ec5]

These training slides about destination signs seem to be fairly California-centric. If you plan to do any mapping elsewhere in the U.S., consider also training mappers on the more standard highway signage used outside of California. For example, ahead of a major split, California uses those very wide overhead signs marking each lane. But many states use a series of smaller signs side by side or a large diagrammatic sign. Diagrammatic signs are being phased out but are still very common. There are also many cases of signs that say “Right 2 Lanes” instead of showing arrows over the specific lanes.

This chapter of the national MUTCD standard (which California doesn’t adhere to) contains numerous diagrams that you may find useful for enhancing the training materials.

destination:street=*
destination:street:to=*

Valhalla uses destination:street and destination:street:to to place a more appropriate preposition before the street name in guidance instructions. OSRM also uses destination:street as a fallback for when there’s no destination. However, other routers have declined to support either tag for various reasons, for example osmandapp/OsmAnd#3592. If you tag a way with both destination and destination:street, you should expect that only Valhalla will include both tags in guidance instructions for the time being. It makes an assumption about the order of destination:street relative to destination on signage that doesn’t hold up in every situation. CheckAutopista2, a sign simulator that’s handy for QA’ing OSM destination data, simulates destination:street according to Valhalla’s behavior.

Some states additionally distinguish between a road that is a destination and a supplemental road name (a name that the route is also known by). Here are some examples, but note that the overall proposal on that page is dormant and will need a rethink in light of Valhalla’s current behavior.

If you choose to tag destination:street, please consider coining some tag to explicitly indicate when a street is listed beneath a non-street destination, as well as a tag other than destination:street for supplemental road names, like perhaps destination:ref:name.

[skudrashou]

Hi, @1ec5 . Thanks for pointing out that our training materials are pretty California-orientated. In order not to overload the current training materials, but at the same time, to give an accurate context of the situation, we will create a group of documents with best practices that relate to local features of destination signs. We will also share these docs with the community to get valuable feedback.
We’re now running internal discussions around the use of destination:street and destination:street:to tags. I‘m going to share our solution here and on Community Slack later on. We are really grateful for your help and advice. If you have any further questions, feel free to ask.

[1ec5]

Another thing I’ve noticed while mapping in Las Vegas is that lots of advisory speed limit signs at entrance and exit ramps have been tagged maxspeed instead of the correct maxspeed:advisory:

maxspeed	maxspeed:advisory

[makarevitcha]

From August 25th, the Lyft team at OSM doesn't support the added "destinations: lanes" and doesn't add new missing "destinations: lanes".

[1ec5]

We’re now running internal discussions around the use of destination:street and destination:street:to tags. I‘m going to share our solution here and on Community Slack later on.

https://community.openstreetmap.org/t/usage-of-the-destination-and-destination-street-tag-with-the-street-name/101788