Slips and falls are a major cause of injury in the workplace. Slips often occur due to insufficient friction and fluid drainage (traction performance) between footwear and a contaminated flooring. Shoe tread is designed to increase traction performance to prevent slipping. As shoe tread wears down, however, the risk of slipping increases. This dissertation examined changes and causes of progressive shoe tread wear and developed shoe replacement strategies to reduce the occurrence of slips. Aim 1 assessed the traction performance changes of shoes worn artificially and naturally through two longitudinal studies. Under-shoe friction and fluid drainage ability decreased with wear. The largest continuous worn region size of the tread was applied to a hydrodynamic model to predict the film thickness between the shoe and flooring. These findings provide knowledge for how traction performance changes across the life of a shoe. This knowledge may help guide shoe testing standards and guide metrics such as the worn region size to recommend replacement. Aim 2 determined the impact of gait kinetics and shoe outsole hardness on tread wear rate. Peak shear forces and the required coefficient of friction were positively correlated with wear rate, but normal force and hardness were not associated with wear rate. This work shows that footwear and replacement strategies could be designed to accommodate individual kinetics. Aim 3 focused on the development of a low-cost tool to scan the shoe tread, determine the worn region size, and predict slip risk. User-centered design techniques were used to incorporate potential users throughout the product design process. The developed scanner was able to accurately determine the shoe worn region size and subsequently predict slip risk. The tool received a satisfactory approval score from the potential users. Findings from Aim 3 will guide future tool iterations and present important insights for involving potential users in the design of products for preventing falls. Overall, this dissertation quantified changes in shoe traction performance with tread wear, identified factors influencing tread wear, and described the development of a tool to recommend shoe replacement to prevent slip and fall injuries.