SharedStreets have created an open standard for curb restriction data (eg. parking restrictions) and have been working on integrating this standard into OpenStreetMap. The idea is that governments can release curb-restriction data and it can be directly integrated into tools and maps using this standard.
OpenStreetMap and curb regulations
Outlines our thinking on how OSM can store data about curb regulations, and how this can be processed and shared in a standard, structured format
SharedStreets