Bicyclist Intersection Safety Index

Abstract

Each year many bicyclists are injured or killed in intersection-related crashes with motor vehicles. The objective of this study was to develop a macrolevel bicycle intersection safety index (Bike ISI) that would allow engineers, planners, and other practitioners to use known intersection characteristics to prioritize intersection approaches with respect to bicycle safety proactively. Using variables that indicate a higher probability of risk for bicyclists, the Bike ISI identifies which intersection approaches have the highest priority for bicycle safety improvements within a particular jurisdiction. Using video data and online ratings surveys, this study obtained data on avoidance maneuvers and safety ratings at 67 intersection approaches and developed a Bike ISI model that incorporated both measures of safety. The Bike ISI uses data on the traffic volume, the number of lanes, the speed limit, the presence of a bike lane, the presence of parking, and the presence of traffic control to give a rating for an intersection approach according to a six-point scale. Using the Bike ISI, practitioners have the ability to evaluate each approach at all intersections in their jurisdictions or at a select group of intersections. Once safety index values are assigned to each site, the practitioner can then select the sites with the highest index values and conduct more detailed reviews of those sites to determine whether any treatments are needed to improve the safety of the intersection.

A Statistical Approach to the Estimation of Bicycle Level of Service Models for the Cicloruta in Bogota, Colombia

“…Few studies that estimated intersection BLOS exist [30], [36], [37] and even fewer have considered a joint estimation of intersection and segment. Carter et al [30] developed an intersection safety index for North Carolina using the generalised linear models, while Landis et al [36] developed a Pearson Correlation and Factor Analysis-based methodology in estimating intersection LOS for the Florida Department of Transportation (FDoT). Some of these studies provided background for choice of intersection variables which were revised to reflect local transport conditions in Bogota.…”

“…Each segment of the roadway was rated by bicyclists as they rode around. In order to provide insight into the ability of transportation planners to evaluate the level of safety in intersections, the bicycle intersection safety index (ISI) was developed in North Carolina using video data and online safety ratings of 67 intersections [30]. Other variables include 'traffic volume, the number of lanes, the speed limit, the presence of a bike lane/parking and the presence of traffic control to a given rating for an intersection approach according to a six-point scale' [30].…”

Development of a Safety Index to Identify Differences in Safety Performance by Postal Delivery Motorcyclists Based either in Different Regional Post Offices or within the Same Regional Office

“…Studies have shown that measuring the SI can facilitate better understanding of factors improving personnel safety [13,14]. The main functionality of the postal motorcyclist monitoring system is quantitative assessing the postal motorcyclists' safety performance by providing SI.…”

“…In fact, obtaining absolute numerical measurements of driving performance is difficult and so relative numerical measurements have been used to evaluate driving performance. Studies have shown that the SI can be effective in identifying the relative safety level of drivers [13,14]. The SI is formulated based on driving behavior as well as those environmental factors that are likely to affect driving behavior.…”

“…The SI is formulated based on driving behavior as well as those environmental factors that are likely to affect driving behavior. Castignani et al [13] consider real-time contextual information, such as route topology or weather conditions; Carter et al [14] consider the variables indicating a higher probability of risk such as traffic volume and roadway geometry in measuring a bicyclist's SI. In addition, the SI is commonly used to evaluate road safety [15][16][17].…”