This is an interactive map outlining each and every street closure for the DNC, complete with times and more information.
If you click on the street, it should tell you when that street will be closed. Also, there are icons for vehicle and pedestrian checkpoints, the transit center and the last light rail stop. Shaded in areas will either require a credential or a security screening, depending on the day/time.
To view in a larger window, click the link here: Where You Can/Can't Go During the DNC