OpenStreetMap: all roads, downloaded from GeoFrabrik.
GTFS: Public transport time schedules. Downloaded from OVapi, for various dates.
TomTom congestion data: obtained from PBL, for various months and years.
Fietstelweek: measured bike speeds per link for 2015, 2016 and 2017. Downloaded from Cycling Intelligence and geographically linked to the OSM network.