Drivers’ Ability to Detect Traffic Signs on Curves with the Presence of Clutter in the Visual Field: A Systematic Review

Abstract

Road accidents are a leading cause of death worldwide. Driver performance and safety can be compromised by various factors, including those related to driver behavior, the road and driving environment, as well as the vehicle itself. Traffic signs play a vital role in informing drivers and increasing their situational awareness. Therefore, it is crucial to detect and understand traffic signs clearly without adding unnecessary workload or compromising driving safety and performance. However, when traffic signs are placed on curves or in visually cluttered environments, or both together, it can increase the demands of driving and potentially compromise safety. A review was conducted to explore recent research on drivers’ ability to detect traffic signs, driving performance, and visual search in curved environments with visual clutter. The analysis revealed that billboards, particularly electronic ones, are generally distracting and may adversely affect driving performance and safety. Additionally, a majority of the reviewed studies on driving on curves indicated decreased performance and a high mental workload. To conclude, this review aims to enhance understanding of driving safety and performance when navigating horizontal curves. It aims to offer recommendations to road engineers concerning the optimal placement of traffic signs and billboards, particularly around curved sections. Generally, it is recommended to minimize the placement of billboards and unnecessary signs on curves to reduce visual clutter and alleviate the driver’s workload when searching for the crucial signs, and thus minimize distractions.