title: Multi-mode reliability-based design of horizontal curves.
abstract: Recently, reliability analysis has been advocated as an effective approach to account for uncertainty in the geometric design process and to evaluate the risk associated with a particular design. In this approach, a risk measure (e.g. probability of noncompliance) is calculated to represent the probability that a specific design would not meet standard requirements. The majority of previous applications of reliability analysis in geometric design focused on evaluating the probability of noncompliance for only one mode of noncompliance such as insufficient sight distance. However, in many design situations, more than one mode of noncompliance may be present (e.g. insufficient sight distance and vehicle skidding at horizontal curves). In these situations, utilizing a multi-mode reliability approach that considers more than one failure (noncompliance) mode is required. The main objective of this paper is to demonstrate the application of multi-mode (system) reliability analysis to the design of horizontal curves. The process is demonstrated by a case study of Sea-to-Sky Highway located between Vancouver and Whistler, in southern British Columbia, Canada. Two noncompliance modes were considered: insufficient sight distance and vehicle skidding. The results show the importance of accounting for several noncompliance modes in the reliability model. The system reliability concept could be used in future studies to calibrate the design of various design elements in order to achieve consistent safety levels based on all possible modes of noncompliance.
authors.affiliation: Department of Civil Engineering, University of British Columbia, 6250 Applied Science Lane, Vancouver, BC, V6T 1Z4, Canada. Electronic address: m.a.essa@civil.ubc.ca.
authors.forename: Mohamed
authors.initials: M
authors.lastname: Essa
authors.affiliation: Department of Civil Engineering, University of British Columbia, 6250 Applied Science Lane, Vancouver, BC, V6T 1Z4, Canada. Electronic address: tsayed@civil.ubc.ca.
authors.forename: Tarek
authors.initials: T
authors.lastname: Sayed
authors.affiliation: Department of Civil Engineering, University of British Columbia, 6250 Applied Science Lane, Vancouver, BC, V6T 1Z4, Canada. Electronic address: m.hussein@civil.ubc.ca.
authors.forename: Mohamed
authors.initials: M
authors.lastname: Hussein
mesh_terms: D000056:Accident Prevention / Q000379:methods*; D000063:Accidents, Traffic / Q000517:prevention & control*; D001955:British Columbia; D004215:Distance Perception; D004779:Environment Design; D006801:Humans; D008962:Models, Theoretical; D011336:Probability; D015203:Reproducibility of Results; D018570:Risk Assessment; D012449:Safety
keywords: Multi-mode reliability; Reliability analysis; Risk-based geometric design; Safety of road design