Collections of URLs pointing to traffic information portals which contain open data or at least data which is free to use
- Bolzano, Italy documentation here, repo here. See #1
- Turin, Italy documentation here. See #13
- Cologne, Germany, CC BY 3.0, traffic flow. See this blog post
- Jena, Germany
- Darmstadt, Germany
- Hamburg, Germany, WFS Daten
- Nordrhein-Westfalen, DE and other data.
- Entire DE (broken) traffic count only
- Entire DE BASt traffic count only
- Entire UK traffic count only, but here seems to be some traffic flow data.
- Gothenbury, Sweden
- Switzerland traffic count only
- France traffic count only
- Historic Road data in EU
- Netherlands via the NDW. FTP-Server for data and measurements is ftp://83.247.110.3/ , see #2
- Lithuania traffic count only
Many EU data sets are available at the European Data Portal
- New South Wales (looks unfree)
- Victoria
Several entries are take from this stackexchange answer
- nationwide
- Alabama
- Arizona
- Arlington
- California
- Chicago or one specific set
- Colorado
- Delaware Valley
- Florida
- Indiana
- Maine
- Massachusetts
- Michigan (seems to be no longer available)
- Minnesota
- New York City and New York
- North Carolina
- Ohio
- Oregon
- South Carolina
- Tennessee (seems to be no longer available)
- Washington
- Wisconsin
- Open Traffic Data project
- OpenTraffic.io -> seems inactive
- MDM-Portal (coverage will be Europe, free to use): Düsseldorf Germany, NRW Germany, ...
- Datex2 Portal, See more information about the UK data here
- NYC Taxi and Limousine Commission: NYC taxi data, dating back to 2009. See also this blog post and this github repository