Base conditions include the following conditions; the methodology can be adjusted to address situations in which these conditions do not exist:
No heavy vehicles, such as trucks, buses, and recreational vehicles (RVs), in the traffic stream; and
A driver population composed primarily of regular users who are familiar with the facility.
Characteristics such as lane width, total lateral clearance (TLC), median type, and access-point density will have an impact on the free-flow speed (FFS) of the
facility. Curves describing operations under base conditions, however, account for differing FFSs.