Update (May 2019):
Check this new release: https://smoosavi.org/datasets/us_accidents. It contains more than 2.25 million traffic accident records which took place within the US, and will be periodically updated.
The following dataset is recently released and will be periodically updated: https://smoosavi.org/datasets/2019_traffic_weather_events
It covers ...
You can try to get data from OpenStreetMap: the https://www.openstreetmap.org
Data can be downloaded per country or region on GeoFabrik.de: https://www.geofabrik.de/
There is even a nice python package called OSMNX to deal with road network (including bike ways where available): https://osmnx.readthedocs.io/en/stable/
You can select road with their OSM ...
opendata.dc.gov actually has some really nice datasets. DC is also a great choice for this, because it has so much good data over a very small area.
Code for DC has a lot of data too, but unfortunately their data portal seems to be down. You could join their Slack channel and ask them directly, or even stand up their portal yourself.
I'm not 100% they have ...
http://biz.weather.com/WU-Data-API_Data-Package-Demo-Request.html looks like it may have all the data you need. Having said that, I'm viewing this on a small display so I can't tell if there is any free access to this.
Many years later... (to anyone of interest), found this by chance, gyro, accelerometer vs long, lat for a study to predcit is the former one are more accuracte by using RNNs https://databank.illinois.edu/datasets/IDB-5975383