## 3 Study Area  
The study sites were selected in three regions of the KSA: Riyadh, Qassim, and Hail. Each city's urban area accommodates multiple routes and has different urban challenges. Riyadh is the capital and thus faces fast urban growth with complicated issues in terms of infrastructure and accessibility for PWD. Qassim is a big agricultural hub, which means that more services and facilities are in demand against the scale of the growing population. With its diversified topography and tourist appeal, Hail city makes enhancing smooth mobility for PWD a challenge. Such places could present wide variations in urban accessibility challenges while providing generalizable results to similar locations. This study carefully selected specific routes within each city to reflect a variety of urban environments and challenges faced by PWD. First, Riyadh, the capital of the KSA, is situated centrally, as seen in Figure 1. It is a rapidly expanding city, presenting numerous societal, economic, and ecological issues. The population growth rate of Riyadh in the year 1438 AH was 4%, significantly above the global average of 2.5%. This rapid population growth presents issues regarding adequate housing, services, facilities, and job opportunities to prevent potential urban crises [51]. This study identified three routes, which were selected in high-traffic areas that connect major medical centers, tourist sites, and transport hubs, highlighting the need for accessible infrastructure in essential and frequently used locations, with selected footpaths measuring 1850 m, 816 m, and 492 m in length. The first route begins at King Fahd Medical City, a hospital frequently frequented by PWD and healthy individuals. This route, which connects to Prince Sultan Military Medical City, is considered relatively long for disabled people, particularly those who use wheelchairs. It is crucial to evaluate this route as it includes an intersection connecting two medical cities and is frequently used by many individuals with disabilities. The other route begins at Al-Masmak Castle, a historical site popular with tourists, and concludes at King Fahd Road Park, spanning 816 m. There is a path for pedestrians, and for people with disabilities to reach this place, they must cross two junctions. The last route starts at Prince Faisal bin Fahd Stadium and travels up to 492 m to reach the Riyadh Bus Station, known as Salah Al-Din Al-Ayoubi Station. This route only has one intersection. The second city is Buraidah, located in the Qassim region, around 350 km north of Riyadh. In the heart of the most significant agricultural region in Saudi Arabia, Qassim's capital, Buraydah, is the region's commercial and administrative center. It is considered the primary food source for the KSA, with extensive agricultural areas dedicated to growing wheat, vegetables, and dates. Qassim comprises 70 districts with concentrated services, massive commerce centers, and recreational facilities. However, the fast-growing population from other cities is putting a significant strain on these services, while other towns and villages in Qassim lack adequate amenities. In 2019, the population of Buraidah city was 590,312, accounting for 51% of the total population in all cities in Qassim [52]. The urban area included around 42,000 hectares. Three chosen routes effectively characterize urban daily life, such as shopping centers, government facilities, and places frequented by PWD, like the Club for PWD. The routes were evaluated to identify key obstacles, such as junctions and footpaths, that could hinder smooth mobility, providing insights for improvements. The first route starts from a shopping center called Nakheel Plaza and reaches a government police facility. This route is 658 m long, and there is a footpath to facilitate wheelchair users' movement. A single junction along this footpath somewhat hinders PWD's movement.