How are reversible lanes marked?

Answer: B — By double-dashed yellow lines

Reversible lanes are designed to allow traffic to flow in different directions at different times, typically to manage congestion during peak traffic hours. These lanes are marked by double-dashed yellow lines, which signal to drivers that they can enter the lane and that it can change direction depending on the time of day. The use of double-dashed yellow lines indicates that the lane is not permanently assigned to one direction of travel and can be used by vehicles traveling in either direction when allowed. The other markings, such as solid white lines, indicate lanes that are to be kept for a single direction of traffic without alterations. Single dashed white lines separate lanes of traffic moving in the same direction and do not signify reversible lanes. Solid red lines typically indicate areas where stopping is prohibited and are not related to the signaling of reversible lanes. Thus, the correct answer highlights the specific need for clear and distinctive markings that accommodate the unique function of reversible lanes.