Velocidad de vehículos en carreteras de montaña: Modelos matemáticos

Abstract

Mathematical models were developed for the estimation of vehicles speed at curves and tangents on a mountainous highway. V85c = 98,25 - 2.795 x (1/Rc)- 894x(1/Ra)+ 7,486 x D + 9,308 x La; Vc = 87,78 -2.251 x (1/Rc)-739 x (1/Ra)+ 5,081 x D; V85r = 100,69 - 3.032 x (1/Ra) + 27,819 x La; Vr = 87,65 - 2.064 x (1/Ra) + 17,353 x La Where: V85C = 85th percentile of speeds at curves (Km/h); Vc = Mean speed at curves (Km/h); V85r = Percentile of speeds at tangents (Km/h); Vr = Mean speed at tangents (Km/h); Rc = Curve radio (m) D = S/250; S = Minimum sight distance at the curve (m); La = Length of the tangent preceding the curve (Km); Ra = Radio of the preceding curve (m). Speeds adopted by drivnes do not depend on the design speed chosen by the engineer, but on the geometric characteristics of the highway. A procedure is proposed which takes advantage of having a design speed and at the same time it takes into consideration the behavior of drivnes on the highway. At a curve drivers consider two measures of efficiency: speed and confort; interchanging one by the other. At some curves they prefer feeling some amount of unconfort in exchange for reaching higher speeds. It can be that for some geometric conditions, drivers adopt a speed such that in addition of sacrificing confort, they also sacrifice safety.