An Analysis of the Impact of Ramp Designs on Wheelchair Users' Travel Time

Abstract

Currently, as Thailand officially has reached the stage of a completely aged society, there is an urgent need to have infrastructure that truly serve the elderly and disables, particularly when it comes to navigating different floor levels that are essential of buildings in terms of safe, equitable, and barrier-free access for all, so that users with limited physical capacity are able to move independently and with dignity within built environments. Beyond daily convenience, these features become a lifeline during emergency evacuations, such as fires or earthquakes under limitation of the physical mobility, when time constraints and physical stress significantly increase, a well-designed ramp is what makes a rapid and safe escape possible for everyone.           

The concept of Universal Design has become a cornerstone in creating environments where everyone, regardless of physical ability, can enjoy equal access, emphasizing usability, safety, and inclusiveness throughout the design process. Among various architectural features, ramps stand out as a clear reflection of this inclusive philosophy. Although there are well-defined standards for slope gradients, widths, and landing placements, many ramps in practice still fail to function effectively in terms of moving—a factor that directly impacts the safety and evacuation efficiency of wheelchair users, particularly under continuous movement and emergency conditions. This research, therefore, focuses on analyzing the relationship between ramp configurations and movement to build a comparative body of knowledge as a practical guide for appropriately designing ramps. 

The study aims to examine and compare various ramp configurations, specifically focusing on how they influence the moving wheelchair users. The research also seeks to propose design solutions achieving optimal time efficiency while staying true to Universal Design principles and official standards. The study implements an experimental approach through computer simulation, utilizing Pathfinder. This software was selected for its specialized capability to model individual wheelchair movements and account for complex, real-world ramp geometries. This makes it an ideal tool for accurately analyzing movement durations within a controlled, simulated environment.

The study’s sample consists of 81 distinct ramp models, generated through a systematic cross-analysis of four key variables including 1) ramp configuration (straight, L-shaped, and U-shaped), 2) landing placement (at the start, midpoint, and end of the ramp), 3) width (1.50, 1.80, and 2.00 meters), and 4) slope gradient (1:12, 1:13, and 1:14). To ensure the integrity of the comparative analysis, a standard manual wheelchair was used as the baseline for all simulations. Furthermore, specific parameters—namely horizontal speed and downhill speed multipliers—were kept constant across every model. This hard control of variables ensures a standardized environment, allowing for a precise and reliable comparison of how different designs affect movement.         

The simulation model is primarily designed to evaluate movement efficiency through a temporal lens. Within the Pathfinder environment, travel paths are calculated based on the central axis of the ramp and landing geometries, strictly following the physical layout without diagonal shortcuts or the inclusion of complex biomechanical factors related to wheelchair handling. Consequently, the simulation results are intended to provide a controlled comparison of time differences across various ramp configurations under identical conditions. The generated data were then analyzed using descriptive statistics and the calculation of an Efficiency Index (EI) to compare the temporal performance of each design. An EI value approaching 100 signifies superior time efficiency relative to other models within the same group, serving as a clear metric for performance evaluation.          

The findings revealed that ramp configuration is the most influential factor affecting the movement of wheelchair users. Specifically, L-shaped ramps demonstrated the highest time efficiency with an average EI of 98.7%, followed by straight-run ramps at 96.1%. The U-shaped configuration yielded the lowest efficiency at 91.5%, a result of the 180-degree turns disrupting movement continuity and inherently increase movement duration. Regarding slope gradients, the 1:12 ratio required the least travel time compared to 1:13 and 1:14; however, the efficiency ranking of the ramp shapes remained consistent across all gradient levels. Interestingly, increasing the ramp width from 1.50 to 2.00 meters led to a slight increase in movement across all models—suggesting that while wider paths enhance comfort and safety in practice, they also extend the movement duration. Finally, mid-point landings were found to provide the most balanced and fluid movement rhythm, whereas end-of-ramp landings tended to increase travel time slightly due to the extended travel distance.        

In summary, this research highlights that ramp designs featuring continuous pathways, optimal turning angles, and standard-compliant gradients significantly enhance the travel efficiency of wheelchair users within simulated environments. These benefits remain consistent across both routine usage and time-sensitive scenarios. The findings align closely with Universal Design principles, particularly in terms of spatial clarity and accessibility. Ultimately, this study serves as a robust evidence-based resource to support informed design decisions for public buildings and spaces, ensuring they effectively accommodate a diverse range of users and promote a more inclusive built environment.