Session: 02-08-01: Advances in Human Modelling

Paper Number: 145050

145050 - Adjustable Pedals in Automotive Design: A Digital Human Modeling-Based Clearance, Clash, and Reach Design Study 

Adjustable features commonly found in modern automobiles, such as steering wheels, mirrors, and seats, help ensure a good driver-vehicle fit, positively impacting comfort and safety. Despite the critical importance of the driver’s ability to reach the pedals adequately, only a limited number of vehicles offer manual or power pedal adjustability. This paper aims to present a computational approach via digital human models (DHM) to explore improvements in automotive occupant packaging with the inclusion of adjustable pedals.

Concerns about the limited or lack of pedal adjustability in modern automobiles come in different forms, including (i) comfort and safety for shorter drivers, especially for pregnant women; (ii) driver fit and clash in compact and performance cars; (iii) leg room for rear-seat passengers.  According to the National Highway Traffic Safety Administration (NHTSA), drivers should maintain a minimum of 10 inches (25.4 cm) from the steering wheel. However, a previous study found that of the smallest 10% of female drivers, 35% of them positioned themselves closer than this recommended distance. Additionally, a study revealed that pregnant women often need to move their seats close to the steering wheel for sufficient pedal reach, resulting in inadequate clearance between their abdomens and the steering wheel. Injuries and fatalities from airbag deployment are also a concern when drivers need to position their seats all the way forward. Research on airbag-induced injuries to drivers discovered that shorter drivers are more likely to sustain injuries from airbags due to their proximity to the steering wheel. Further, a forward seating position has been found to increase the risk of lower limb injury to smaller drivers as their knees tend to become trapped under the instrument panel. It is important to note that certain types of vehicles, such as high-performance sports cars, do not feature seat adjustability, increasing the need for alternate design solutions. For example, the Mercedes-AMG One and Ferrari Daytona SP3 have fixed bucket seating and adjustable pedal systems to allow drivers with varying anthropometries to achieve their preferred positions for accessing the pedals.

In this study, we explore how the implementation of adjustable pedals impacts occupant packaging in specific "what-if" design scenarios via a computational design framework that uses DHM within a low-fidelity computer-aided design (CAD) modeling environment. This approach provides proactive ergonomics and informs designers in assessing fit-, clash-, and comfort-related scenarios based on computational manikins. The specific occupant packaging case studies include implementing adjustable pedals in generic concept automobile designs with adjustable and fixed seat configurations. These studies help assess how pedal adjustability impacts driver-vehicle fit (e.g., clearance and clash) with varying driver anthropometries, including pregnant, non-pregnant, and male occupant models. The results compare the outcomes of interest regarding clearance and clash both “before and after” the adjustable pedals implemented in concept vehicle models.

Presenting Author: Gabrielle B. Joffe Oregon State University

Presenting Author Biography: Gabrielle B. Joffe is an undergraduate student in Mechanical Engineering at Oregon State University. She previously completed a six-month internship as a Manufacturing Engineer at The Boeing Company. Her research interests include human factors engineering, human-centered design, and digital human modeling. She will begin a Master of Science degree in Mechanical Engineering at Oregon State University in September 2025.

Authors:

Gabrielle B. Joffe Oregon State University
H. Onan Demirel Oregon State University