Finding and characterizing hidden dips in roads

Abstract

Abstract. Sometimes when connecting a crest vertical curve, followed by a sag and another crest, a road disappears from the view of a driver to reappear later. Then, there is a loss of path or a hidden dip in a road. It is essential to avoid losses when they hide dangerous points, such as intersections or unexpected changes in direction. In addition, this loss disrupts drivers and its effect depends on quantitative relationships between the variables involved in the problem. This paper presents a quantitative procedure for studying hidden dips in roads. The method is based on calculating the sections visible and hidden by a driver using a Geographic Information System. An application to a Spanish road is presented. Procedure results were compared with in situ carried out studies and with a video of the highway recorded using a Global Positioning System equipped video camera embarked in a vehicle. The main quantitative issues related to hidden dips are discussed.

Three-Dimensional Virtual Highway Model for Sight-Distance Evaluation of Highway Underpasses

“…In this regard, the most relevant issues for highway safety were known to be hidden horizontal curves and sight-hidden dips (Zimmermann and Roos 2005;Kuhn and Jha 2011). Several studies have sought to characterize sight-hidden dips and the potential effects of them on safety (De Santos-Berbel and Castro 2016; Castro et al 2015a). Moreover, Castro et al (2014b) quantified the parameters of sight-hidden dips using measurements taken from photographs.…”

Performance improvements of asphalt mixtures by dry addition of polymeric additives

“…These charts represent on the horizontal axis the stations where the driver is sequentially placed, and on the vertical axis the sight distance variables ahead each driver position (Kühn & Jha 2011, Castro et al 2014. Besides the comparison available and required sight distances, such charts result advantageous to evaluate the 3-D alignment coordination (Roos & Zimmermann, 2004, Jha et al 2011, Castro et al 2015a ABSTRACT: As one of the main elements of geometric design, sight distance must be considered carefully for the safe and efficient operation of highways. An application developed on geographic information systems (GIS) was conceived for the three-dimensional estimation of sight distance on highways, as opposed to conventional two-dimensional techniques, which may underestimate or overestimate the actual visibility conditions.…”