Microsimulations of traffic systems require detailed input data about the road network, public transit, and land use (to estimate travel demand). At SOTM-EU Vienna, I introduced our simulation model (MATSim) and remarked that OSM had already become our preferred source for road network data. Since then, we have created several simulation scenarios from OSM, and we created a JOSM plug-in to export network data to MATSim (encouraging researchers to contribute corrections back to OSM instead of making them locally in the target format). I would like to report on the joint experience of the MATSim community using OSM data from diverse cities (including public transit tagging), and introduce traffic simulation to the OSM community at large.