I always say that in tight , high traffic spaces that you shouldn't be afraid to "take the lane". If i'm worried about traffic trying to squeeze by me when there isn't much of a shoulder (if any) for me to ride on I always scoot myself into a very visible spot--in the center if not even slightly to the left of the center of the lane to make myself visible. Even if traffic needs to get stacked up behind me for a little while it's better than us trying to share the road in a place that is not big enough for both of us...because if push comes to shove--the car will win!