What does the formula L = W * S refer to for speeds of 45 mph or more?

The formula L = W * S is utilized to determine the length of a merging taper, which is critical in traffic engineering for facilitating the safe merging of vehicles from one lane to another, particularly when the traffic speeds are 45 mph or higher. In this formula, "L" represents the length of the taper, "W" is the width of the lane being added, and "S" stands for the speed of traffic.

This relationship is established to ensure that as vehicles merge, they have adequate distance to adjust their speed and align safely with the existing traffic flow. The taper allows for a gradual transition rather than an abrupt lane change, thereby enhancing safety and flow efficiency.

For traffic speeds of 45 mph or more, the merging taper is especially crucial, as higher speeds demand longer distances for vehicles to merge without causing collisions or disruptions to traffic. This is why the merging taper is the correct answer, as it directly relates to the use of the formula in managing lane assignments in high-speed scenarios.