What do you consider "the bottom"? Rock Creek Parkway ends and Beach Drive begins at the Connecticut Avenue Bridge. I find the whole of Beach Drive to be comortable riding, but I would never on Rock Creek Parkway unless I was with big group. It's too fast and windy. You're right, however, that there are no shoulders, but the drivers have never given me any problems. But I will admit that Beach Drive gets quieter north of Piney Branch Parkway.