Continues roll makes sure the banking is a little more fluent.
If you would create a barrel roll in 4 sections and you would set the banking on each node to 90, 180, 270 and 0 again. Without continues roll the actual 'rolling' would be segmented. With the Conroll turned on, the rolling will be fluent throughout the element.
However there are limits to this. If you have small segments next to large segments, the conroll might over- or underdo things, creating pumps in the tracks. Also, conroll should not be turned on by nodes that start or end a brake/lift or station segment, as those segments must remain perfectly straight.