Vehicle speed and lateral distance when passing bicyclists on rural roads

Tuesday, June 10, 2025

4:45 PM – 6:00 PM MT

Primary Author(s)

Boris R. Claros, n/a

Scientist
University of Wisconsin-Madison
MADISON, Wisconsin, United States

Co-Author(s)

Boris R. Claros, n/a

Scientist
University of Wisconsin-Madison
MADISON, Wisconsin, United States
Madhav A. Chitturi, n/a

Scientist
University of Wisconsin-Madison
Madison, Wisconsin, United States
Andrea Bill, n/a

Associate Director
Traffic Operations and Safety Laboratory, UW-Madison
Madison, Wisconsin, United States

Presenter(s)

Andrea Bill, n/a

Associate Director
Traffic Operations and Safety Laboratory, UW-Madison
Madison, Wisconsin, United States

Co-Author(s)

David A. Noyce, n/a

Executive Associate Dean and Arthur F. Hawnn Professor
University of Wisconsin-Madison Department of Civil and Environmental Engineering
Madison, Wisconsin, United States

Presenter(s)

David A. Noyce, n/a

Executive Associate Dean and Arthur F. Hawnn Professor
University of Wisconsin-Madison Department of Civil and Environmental Engineering
Madison, Wisconsin, United States

Submitter(s)

Boris R. Claros, n/a

Scientist
University of Wisconsin-Madison
MADISON, Wisconsin, United States

Abstract: Among vulnerable roadway users, of concern are bicyclists riding on rural roads because of limited design guidance and existing infrastructure that prioritizes high speed vehicular operations where bicyclists are allowed to ride on the travelway without equitable access to bicycle dedicated lanes, shoulders, separated paths, or sidewalks. In 2022, there were 1,105 bicyclist fatalities and an estimated 46,195 bicyclists were injured in vehicular crashes in the United States. To address bicycle safety concerns in rural roads, it is important to understand driving behavior and interactions with bicyclists to raise awareness of risk mitigating strategies to systematically improve infrastructure and roadway transportation culture. Bicyclists are exposed to potential vehicle contact collisions which may result in higher rates of severe injury and fatality due to the nature of proximity and higher relative speed in rural roads. A bicycle naturalistic study was conducted to evaluate vehicles’ speed and lateral clearance when passing bicyclists. Driving behavior joint probability density functions of lateral distance and speed of vehicles passing bicyclists were developed for leading and follower vehicles which contribute to specify and validate driving simulator studies or autonomous/artificial intelligence driving models. Due to the complexity, risk, and limitations of collecting bicycle naturalistic or observational data, simulations can contribute to continue studying driving behavior in controlled environments or training of models to safely pass bicyclist in rural environments.

Learning Objectives:

Attendees can expect to learn the following from this session:

Understand the challenges faced by bicyclists on rural roads, including infrastructure limitations and high-speed vehicle operations.
Assess how vehicle speed and lateral distance when passing bicyclists influence safety outcomes and the risk of collisions.
Interpret joint probability density functions of vehcile speed and lateral distance for vehicle driving behavior