title: Risk assessment in ramps for heavy vehicles--A French study.
abstract: This paper presents the results of a study dealing with the risk for heavy vehicles in ramps. Two approaches are used. On one hand, statistics are applied on several accidents databases to detect if ramps are more risky for heavy vehicles and to define a critical value for longitudinal slope. χ(2) test confirmed the risk in ramps and statistical analysis proved that a longitudinal slope superior to 3.2% represents a higher risk for heavy vehicles. On another hand, numerical simulations allow defining the speed profile in ramps for two types of heavy vehicles (tractor semi-trailer and 2-axles rigid body) and different loads. The simulations showed that heavy vehicles must drive more than 1000 m on ramps to reach their minimum speed. Moreover, when the slope is superior to 3.2%, tractor semi-trailer presents a strong decrease of their speed until 50 km/h. This situation represents a high risk of collision with other road users which drive at 80-90 km/h. Thus, both methods led to the determination of a risky configuration for heavy vehicles: ramps with a length superior to 1000 m and a slope superior to 3.2%. An application of this research work concerns design methods and guidelines. Indeed, this study provides threshold values than can be used by engineers to make mandatory specific planning like a lane for slow vehicles.
authors.affiliation: Lunam, Ifsttar, Laboratoire EASE, Route de Bouaye, CS4, 44340 Bouguenais, France. Electronic address: veronique.cerezo@ifsttar.fr.
authors.forename: Veronique
authors.initials: V
authors.lastname: Cerezo
authors.affiliation: CEREMA, DTer CE, Département Laboratoire de Clermont-Ferrand, 8-10, rue Bernard Palissy, 63017 Clermont-Ferrand Cedex 2, France.
authors.forename: Florence
authors.initials: F
authors.lastname: Conche
mesh_terms: D000063:Accidents, Traffic / Q000706:statistics & numerical data*; D001107:Architectural Accessibility; D004738:Engineering; D004779:Environment Design; D005602:France; D006801:Humans; D018986:Motor Vehicles; D018570:Risk Assessment
keywords: Heavy vehicles; Longitudinal slope; Ramps; Speed profile; Statistical analyses