When estimating free flow speed in the HCM procedure for analyzing basic freeway segements, select all of the factors that are considered to affect the estimate of free flow speed. a. Lane widths greater than 12' The percent of trucks, buses and RVs in the traffic stream.
b. Right-side lateral clearences of greater than 6'
c. The number of ramps located between 3 miles upstream and 3 miles downstream of the midpoint of the basic freeway segment under study Lane widths less than 12'
d. Right-side lateral clearences of less than 6' The peak hour factor.