What do advanced stop lines do?

Answer: B — Allow cyclists to position in front of traffic

Advanced stop lines, also known as "bike boxes," allow cyclists to safely position themselves in front of traffic at a red light. This gives them a head start when the light turns green and increases their visibility to drivers. Option A is incorrect because advanced stop lines do not regulate traffic speed, but rather provide a safe space for cyclists to stop. Option C and D are also incorrect as advanced stop lines do not indicate bus-only zones or mark pedestrian crossing areas.