Recently, a new procedure for analyzing multilane highways was proposed, together with a set of speed-flow curves that were rather different from those in the highway capacity manual (hcm). Consideration is given to whether a freeway basic section treated as a multilane divided highway section with no access points can be analyzed using this procedure. The speed and flow characteristics of a freeway section (california state highway 24) at the caldecott tunnel are examined and compared with the speed-flow curves in the hcm for freeways and those in the new procedure for multilane highways. The problems associated with traffic data gathering, reduction, and analysis are also reviewed. It was found that the new procedure reflects the speed-flow characteristics at the caldecott tunnel better than the hcmprocedure for freeways. This paper appears in transportation research record no. 1320, Freeway operations, highway capacity, and traffic flow 1991.
Abstract