Calibrating Design Guidelines using Mental Workload and Reliability Analysis

Abstract

The generic nature of road design is indiscriminate to age, race, or gender, as it is implicitly assumed that there are few behavioral differences between drivers while traversing various alignment elements (e.g., horizontal curves, tangential segments, etc.). For instance, the perception reaction time required, which is based on an 85th percentile value, on a tangent section is the same as that on a horizontal curve. This suggests that current guidelines do not consider the complexity that some geometric features might induce on drivers, and consequently, there is a need to address the many considerations of diversity. In this respect, human factors should be explicitly included in design guidelines. One aspect of human factors that has received little attention in the literature is related to the mental workload. In this study, a procedure is presented to estimate the mental workload for stopping sight distance. Then, reliability analysis is conducted to compare the change in the probability of non-compliance owing to the available sight distance and based on the mental workload. By analyzing data from 12 horizontal curves in Alberta, Canada, the probability of non-compliance dropped from 9.1% to 0.7%, and a moderate correlation with collisions was found. The results of the analysis showed that incorporating mental workload into the geometric design process can improve safety performance.

A system to determine advisory speed limits for horizontal curves based on mental workload and available sight distance

“…This result might relate to the increased complexity of the driving situation, as the combination of two aforementioned geometric elements would likely require additional ASD. For example, (Habib et al 2020) examined the credibility of the SSD framework as provided by (Messer 1980) using reliability analysis. The results of reliability analysis, which compared the results of stopping sight distance based on MWL requirements versus the available sight distance, showed the applicability of Messer's framework and its readiness for further applications.…”

“…Recent literature suggests that there is a link between available sight distance (ASD) and highway safety (Ibrahim et al 2012;Lanzaro et al 2020). For example, (Habib et al 2020) found that the probability of non-compliance dropped from 9.1 % to 0.7% when the MWL for SSD (MWL SSD ) was examined in conjunction with the ASD on horizontal curves. Likewise, a study by (Gargoum et al 2018a) revealed that collision rates increased 2.1-fold among aging drivers most notably on sections of highways with restricted SSDs.…”

Octree‐based point cloud simulation to assess the readiness of highway infrastructure for autonomous vehicles

“…A horizontal or a vertical curve redesign may be considered for highly sharp curves to improve vehicles’ travel speed and reduce delay. This is possible as extracting horizontal or vertical curve parameters is viable using LiDAR data (Gargoum, El‐Basyouny, Shalkamy, & Gouda, 2018; Gouda, El‐Basyouny, & Mello, 2020; Habib, Gouda, & El‐Basyouny, 2020; Habib, Shalkamy, & El‐Basyouny, 2019; Shalkamy & El‐Basyouny, 2020). Using ASD and curve parameters, new requirements for longer ASD can be determined, and a new pavement surface layer can be designed.…”

Automated Object Detection, Mapping, and Assessment of Roadside Clear Zones Using Lidar Data

“…To determine this, transportation agencies have traditionally needed to manually document roadside clear zone size and slope, and the position of obstructions on a case-bycase basis. Recently, however, because of its millimeterlevel accuracy, reduction in cost, and widespread data collection capabilities, civil engineering research has shifted to the use of lidar as a fast and feasible alternative for data collection (14)(15)(16)(17)(18)(19)(20).…”