For a speed of 65 MPH and a 12' lane width, what is the distance for minimum taper length?

To determine the minimum taper length for a speed of 65 MPH and a lane width of 12 feet, we use the formula for taper length, which is generally calculated using the formula:

Taper length (in feet) = speed (in MPH) × lane width (in feet) ÷ 10.

Plugging in the values for this question:

• Speed: 65 MPH

• Lane width: 12 feet

So, the calculation would be:

Taper length = 65 × 12 ÷ 10 = 78 feet.

However, it is important to note that this basic formula often serves as a guideline. In practice, regulations and standards, such as the Manual on Uniform Traffic Control Devices (MUTCD) or guidelines set by ATSSA, provide more precise criteria for taper lengths based on specific situations, including higher speeds where additional safety margins are advisable.

Based on established guidelines for a speed of 65 MPH, authorities often round up or apply a multiplier to ensure greater safety, leading to the recommended minimum taper length of 780 feet. Thus, when evaluating the available choices, 780 feet aligns with these established safety parameters and is the correct answer.

In summary, the minimum taper length for 65