Describe the situations that require adjustments from the base conditions for multilane highway capacity analysis.

Question

What will be an ideal response?

Answer 1

Base conditions for multilane highways include the following elements (other
characteristics such as total lateral clearance (TLC), median type, and accesspoint
density will also impact the FFS of multilane highways). If one or more of
the following conditions is not met, base conditions require adjustments.
(1) Weather and driver visibility are good and do not affect traffic flow.
There are no obstructions that could impede traffic flow such as incidents,
accidents or roadwork. The HCM procedures are based on the assumption
that each condition is met. If this is not the case, the speed, LOS and capacity
is likely to be lower than estimated.
(2) The traffic stream is composed solely of passenger cars and there are no
heavy vehicles such as trucks, buses and recreational vehicles (RVs).
(3) All drivers in the traffic stream are regular users and are familiar with the
freeway segment.