||Slips and falls during egress from heavy truck cabs are a major contributor to injury and disability for truck drivers. A large-scale laboratory study was conducted to quantify the dynamics of ingress/egress (IE) for Class 7 and 8 commercial truck cabs. A simulated truck cab was constructed in a laboratory allowing manipulation of many geometric variables affecting ingress and egress. Experienced commercial truck drivers were recruited to participate. Subjective responses and anthropometric information for all participants were obtained along with detailed biomechanical data, including whole-body kinematics and reaction forces on the ground, steps, and handholds. This study involves three-dimensional reconstruction of truck driver egress motions, detailed analysis of spatiotemporal parameters and driver behaviors (i.e., IE tactics), as well as a description of access system egress cycles and methods of analyses. In addition, the influence of cab design and driver anthropometric and behavioral factors on biomechanical parameters are investigated. This research also provides a detailed quantitative description of the driver interaction with the cab elements (steps and handholds) and presents valuable insight into the dynamics of cab egress that will allow for a more accurate definition of etiological risk factors for slipping during truck cab egress. In summary, driver biomechanics largely depends on their interaction with the cab, tactics, foot behaviors, and the quality of contact with the steps. In general, during egress, study participants used the right handhold most frequently, followed by the door handle and then the steering wheel. Findings from this research also indicated that a portion of drivers performed egress facing away from the cab and given the prevalence of high body mass index (BMI) among this population, handhold and step location and design should incorporate the base of support (BoS) and stability metric calculations to allow such population for proper "footing" and allow for their center of mass (CoM) to be as close to the truck as possible in the event the drivers utilized the facing away egress tactic. Finally, BMI is a factor that has been associated as an indicator of increased level of risk. Therefore, driver training should include opportunities to get the drivers' weight lowered and fitness level increased. Additionally, drivers may also benefit from stability and strength training as stair stepping is physically more demanding and requires more stability when compared to walking.