4. A long section of freeway is to be designed on level terrain. A level section of 3 km. However is followed by a 2.5 km. with 5 % grade. If the DDHV is 2400 vph with 10 % trucks and 3 % RVs, how many lanes will be needed on the
a) upgrade, b) downgrade, and c) level terrain section to provide for a minimum of level service C? Assume that acceptable lane widths and lateral clearances are to be provided, and that drivers are generally regular users of the facility. The PHF is 0.95.