The parts of Bethesda and Chevy Chase I have driven through this morning have well-treated roads, for the most part. Watch out for the occasional ice patch.
It is currently 14°, but the snow is light in texture, which is a positive for cleaning off cars, and for road conditions. As you can see in these photos taken near the Friendship Heights Metro station and Mazza Gallerie, roads are in good condition. Today's high will be 24° around mid-afternoon, with temperatures plunging to a low of 6° by 6 AM tomorrow morning.