What additional consideration should be given to the sight distances computed in Problems 7-20 and 7-22 for the design vehicle crossing the intersection?

Question

What will be an ideal response?

Answer 1

Minimum requirements determined for right and left turns as presented for Cases B1 and B2 will usually satisfy the requirement for the crossing maneuver. AASHTO, however, recommends that the available sight distance for crossing be checked when the following conditions exist:
? when only crossing maneuver is allowed at the intersection;
? when the crossing maneuver will involve an equivalent width of more than six lanes, or
? where the vehicle mix of the crossing traffic includes a substantial number of heavy vehicles and the existence of steep grades that may slow down these heavy vehicles while their back portion is still in the intersection.