The Use of Gantries and Cantilevers at a Redesigned Intersection: a Simulator Study on Route Choice and Visual Search Behavior

Abstract

Designing a roadway should take into account a Safe System Approach which tolerates human errors, and can be supported by understanding the traffic operational safety effects by means of computerized design assistance tools and techniques. Signalization is an essential factor in this design and determines route and lane choice and wayfinding for drivers. This case study, performed for the Flemish Agency for Roads & Traffic, combined real-life videos with virtually simulated road environments to compare two signalization concepts; gantries and cantilevers. Twenty-two participants drove six different routes in a medium fidelity fixed-base driving simulator with a mock-up in front of a single projection screen. A within-subject design was used with origin (3 levels), destination (2 levels) and signalization (2 levels) as independent variables, and visual search behavior and accurate lane choice, at three fixed locations, as dependent variables. Compared to cantilevers (range from 28% to 56%), optimal lane choice percentages were higher in case gantries were presented (range from 39% to 100%), which translates in capacity and safety gains. Visual search behavior indicated significantly more glances on the gantry than on the cantilever. Consequently, based on this case study, the arterial road in Hasselt (Flanders; Belgium) is equipped with gantries.