The Highway Capacity Manual, HCM, 2000 displayed a figure, Exhibit 10-15, for the purpose of forecasting the likely intersection control types for future facilities. Since this figure is from a source external to HCM, this paper employs HCM methodologies for the estimation and comparison of control delay, the choice measure of effectiveness, at intersections controlled by signal, all-way stop signs, and two-way stop signs to verify it. After detailed analyses of more than 5,000 cases using Highway Capacity Software (HCS), results of control delay with various control types under a wide range of demand conditions were charted for comparison with Exhibit 10-15. It is found that Exhibit 10-15 is inconsistent with the results from HCM methodologies and, perhaps, should be replaced with the figures developed in this paper. Based on the criterion of minimizing delay alone, it was found that if demand is unbalanced, between major and minor streets, and if the traffic is low on minor streets, two-way stop control, or TWSC, should be used; if demand is somewhat balanced and minor streets sees low to medium traffic, all-way stop control, or AWSC, is preferred; otherwise, signal control should be favored. The paper also demonstrates that the percentage of left-turning traffic has a significant effect on decisions regarding intersection control types.
Samenvatting