Zone 30 speed limits: using OSM next to "Verkeersborden Vlaanderen"

“Zone 30” are not always mapped in a coherent way, neither in OSM as in the application Verkeersborden Vlaanderen. As this data is fed into car navigation systems, locals complain why their car GPS system does not reflect the speed limits in their neighborhood. Incentive for change, and for getting to know how OSM and “Verkeersborden Vlaanderen” can help to get real-live improvements such as improved adherance to speed limits.

It would be great if we could compile an “how-to” for locals. I already listed some topics below. But I would greatly appreciate if you could contribute ideas and tools to get to work.

The ultimate goal is better road safety. Here are the to-do’s:

(1) Improving the situation in the streets: Coherent “zones 30” signaled with traffic signs F4a (begin zone 30) and F4b (end zone 30). Any repeat signs have a supplementary sign “herhaling.” Visibility of traffic signs is good (not hidden by plants or other objects). Traffic signs are conform legal requirements and normalized, which is important for vision-based traffic sign detection and recognition and legal enforcement.

(2) Tagging in OSM: “Zones 30” are correctly tagged and coherent; optionally traffic signs are mapped. Correctness and coherence can be checked with Overpass queries like this.

(3) Tagging in Verkeersborden Vlaanderen: Traffic signs F4a/F4b are mapped, as well as other signs that change the speed limit regime (e.g. signs F12a (begin living street) and F12b (end living street). Correctness and coherence can be checked with the application Afgeleide snelheidsregimes - Vlaams gewest. An example is here. Note that we depend on the (local) authorities to correct the registration of their traffic signs in this application. And note that this information is fed into “Transport Network Intelligent Transport Services” (TN-ITS) and commercial navigation systems like TomTom (source).

Questions I can already have are:
(1) Is there a way to process all traffic signs in the “Verkeersborden Vlaanderen” dataset, and map the subset related to “zone 30” and “living streets” and speed limits as an overlay on an OSM map?
(2) Is there a way to compare the “afgeleide snelheidsregimes - Vlaams gewest” maps with the maximum speed limits in OSM?
(3) How can we collect and document all required changes to the actual situation in the streets (e.g. incorrect signalisation) and to “verkeersborden Vlaanderen” in an efficient way, to allow the local authorities to do their job: (a) correct the signalisation in the streets, correct the mapping in “verkeersborden Vlaanderen” (b).
(4) How can we monitor these changes in “verkeersborden Vlaanderen”, as a trigger to update OSM?
(5) How to efficiently update the “zone 30” in OSM for a set of streets?

I look forward to your comments and ideas!

Welkom, @orchi_osm! Sta me toe u te verwittigen: de meeste Belgische OSM’ers gebruiken liever de mailing-lijst dan dit forum, misschien is het nuttiger u aldaar aan te melden ( talk-be @ openstreetmap.org ). Maar er zijn wel een paar brave zielen die af en toe hier ook eens kijken, en uw bericht wel zullen oppikken; alleen kan het een paar dagen duren, misschien.

Hey,

I happen to be one of the few to have an RSS feed for messages here to see what needs to be dealt with.
I can highly recommend the talk-be mailinglist or the chat channel though: https://riot.im/app/#/room/#osmbe:matrix.org

on topic:
there is a dump of the signs I believe, joost schouppe has been in communication with Digitaal Vlaanderen about it. We did notice however that a lot of municipalities have been less then exemplary as to keeping the database updated since it’s original inception though, so caution is required.

(1) Is there a way to process all traffic signs in the “Verkeersborden Vlaanderen” dataset, and map the subset related to “zone 30” and “living streets” and speed limits as an overlay on an OSM map?

There’s a wfs server that has all the traffic signs. It’s doable to extract all the traffic signs.
Using them to calculate “afgeleide snelheidsregimes” would be challenging, to say the least. This has taken AWV a very long time to do, and that whit a road network that has some links to the traffic signs. But perfection is the enemy of useful - you could relatively easily make a proces that says “hey, here is the start of a zone 30,but there is no nearby osm road segment that has maxspeed=30”

(2) Is there a way to compare the “afgeleide snelheidsregimes - Vlaams gewest” maps with the maximum speed limits in OSM?

This could be a great extension to our Road Completion project (see the OSM.be website for more info)

(3) How can we collect and document all required changes to the actual situation in the streets (e.g. incorrect signalisation) and to
“verkeersborden Vlaanderen” in an efficient way, to allow the local authorities to do their job: (a) correct the signalisation in the streets, correct the mapping in “verkeersborden Vlaanderen” (b).

Now that’s a challenge :slight_smile:
At this moment, I don’t think more than one in three municipalities have their data relatively correct in the traffic sign database
We could work with that data to show the rest of them the usefulness of good data, but there is probably not much more we can do from our side.

(4) How can we monitor these changes in “verkeersborden Vlaanderen”, as a trigger to update OSM?

This should be relatively easy again. With the metedata provided, it should be possible to extract new traffic signs and have people check their impact. Preferably only after automatic checking of an update in OSM is needed at all

(5) How to efficiently update the “zone 30” in OSM for a set of streets?

That’s the least difficult part of all :slight_smile:

Thanks for the tip of the WFS server, @Joost Schouppe.

I added the “Verkeersborden Vlaanderen” traffic signs as a layer in JOSM. Now I have the OSM data and a visualisation of the traffic signs in one application :slight_smile: .

How-To for other newbies.

There is a specific WFS-layer of “zone 30” and “zone 50” based upon the verkeersbordendatabank (speed regime 30 and 50 could also be caused by C43-signs or, in the case of 50 km/h, “built-up area” (bebouwde kom):
https://opendata.apps.mow.vlaanderen.be/opendata-geoserver/awv/wfs?REQUEST=GetCapabilities&SERVICE=WFS
Layer: awv:Afgeleide_zones_zone30 or awv:Afgeleide_zones_zone50

After lobbying together with Waze Belgium, there is now an easy way to download all the traffic signs in one shapefile. URL:

https://wegenenverkeer.be/zakelijk/documenten?documents%5B0%5D=type_document%3AOpen%20Data&documents%5B1%5D=type_document%3Aopen%20data

This should also make it easy to make a script that highlights new traffic signs to help us map their impact.