Cycling remains a popular mode of transportation, yet cyclists are vulnerable road users that face numerous safety challenges. Although human factors research typically focuses on motor vehicle drivers, studies addressing active transportation users, like cyclists, are scarce. The unique aspects of cycling, such as physical effort, exposure to the environment, and disconnected infrastructure, can affect cyclists’ mental perception, workload, and behavior, which are argued to influence their safety on the road. Therefore, this scoping literature review identified factors influencing cyclists’ workload and explored different measures used to quantify mental workload. The findings highlighted age, infrastructure, portable devices, and type of bike as factors that could affect workload levels. However, research on cyclists’ workload from their perspective is limited. This paper summarizes three types of workload measure: subjective, performance, and physiological. These have been used to quantify workload in relation to cyclists and in other settings. We reflect on their benefits and challenges were they to be used to quantify cyclists’ workload. Our discussion emphasizes the need for future research to take a comprehensive approach that considers multiple factors simultaneously to gain a more holistic understanding of their collective impact on cyclists’ mental workload. Moreover, we emphasize the importance of supplementing subjective workload measures with psychophysiological ones for better accuracy and reliability. The review revealed a lack of data and guidelines specific to cycling infrastructure, contributing to cyclists’ vulnerability, and underscored the need for previous findings to be translated into actionable recommendations to improve cyclist safety.
This article presents an analysis of the traffic-calming effects of bus rapid transit (BRT) by studying changes to motor vehicle speeds before and after implementation of Albuquerque Rapid Transit (ART) infrastructure in Albuquerque, New Mexico. While ART construction was completed in spring 2018, the BRT buses did not operate until December 2019; providing a unique opportunity to explore the influence of BRT infrastructure sans BRT buses (i.e., to tease apart the effects of BRT infrastructure and operations). We used validated data from StreetLight InSight to compare before/after changes to average motor vehicle speeds and 85th percentile motor vehicle speeds at 46 ART sites and 36 control sites. Findings suggest that infrastructure associated with BRT systems can improve traffic safety by reducing vehicle speeds. Speed decreases at the ART sites were especially strong in terms of 85th percentile decreases, suggesting that the BRT infrastructure is especially effective at limiting excessive speeding. Motor vehicle 85th-percentile speeds along the ART corridor were reduced by 11.5% (compared to a 5.8% decrease at control sites). The 85th-percentile speeds at the ART sites decreased from 32.3 mph to 28.6 mph, which is an especially important range for vulnerable road-user safety outcomes. While ART intersections saw the largest decreases in absolute speeds (a reduction of 4.1 mph in 85th-percentile speeds), ART mid-block sites had larger decreases relative to the control mid-block sites (decreases in 85th-percentile speeds were 73.7% greater at ART mid-block sites than at control mid-block sites). BRT-related lane reductions were linked with particularly strong speed reductions; there were 85th-percentile speed reductions of 4.1 mph (12.6%) when general vehicle lanes were removed versus 2.2 mph (7.8%) when lanes were not removed. Speed reductions were experienced across the ART corridor even though 87.0% of BRT locations did not have a change in posted speed limit, suggesting that physical changes to the roadway associated with BRT were impactful in terms of speed reductions and in turn could possibly promote traffic injury prevention by decreasing the number and severity of crashes.