Try connecting to it as WMs connection.
Simply add a new WMS layer in Display Manager:
Data > Connect to Data > Add WMS Connection
If you were to consider third party add-ons, MapWorks Base will import .OSM files directly into Civil3D (or plain AutoCAD). The files are in lat/long and are projected to a designed plane system assigned to the current drawing.
Access a broad range of knowledge to help get the most out of your products and services.
Start with some of our most frequented solutions or visit the Installation and Licensing Forum to get help installing your software.
Upgrading to a 2015 product? Make sure to check these out 1st!