Appraisal of different HCM methodologies for analysis of weaving segments, case study: a weaving segment in Isfahan, Iran

ABSTRACT

All editions of the Highway Capacity Manual have dedicated chapters to analysis of weaving sections. These chapters are taken as the base of action in many regions of the world including Iran. Therefore, this study aims at evaluate and compare the precision and effectivity of models proposed in four recent editions of HCM. Results indicate that in terms of adaptation with observed values in Iranian highways, the third edition performs best in estimating the speed of non-weaving vehicles, edition six in estimating the rate of lane change, and edition five in estimating the rest of variables and the level of service. Consequently, a combined model is suggested which presents more satisfactory results than the evaluated models. In detailed analysis of the evaluated models, it is determined that simultaneous increase of volume ratio and total demand would increase the discrepancies of the output of these models’ actual values.

KEYWORDS:

• Weaving segment
• highway capacity manual
• field observation
• lane-changing rate
• space mean speed
• density
• level of service
• Isfahan

Disclosure statement

No potential conflict of interest was reported by the authors.