The study has design flaws. Bicyclist Lateral Position . However, why bicyclists ride further from the roadway edge in a BL is unknown, but could be due to greater bravery on the part of the bicyclist, or more curbside debris in the BL which forces the rider further out. Buffer Zone . BLs provide a tangible buffer for pedestrians, especially along roads with no sidewalk setback from the curb.
BLs are also a buffer for drivers pulling out from driveways to enter the roadway.
This is good for drivers, bad for bicyclists who may be obstructed or struck. WOLs are not a formalized buffer, but provide greater separation distance than a standard width lane. BLs are politically difficult to remove once in place. A WOL may be more easily converted to additional travel lanes. This should not be a problem in Chapel Hill however.