This study examines the importance of using remote sensing in road design, especially in regions prone to flooding or irregular terrain. These technologies rely on digital elevation models to provide data on topography and elevations. DEMs also contribute to hydrological studies and identifying areas of water accumulation, aiding in better flood risk assessment and management, improved road design, saving time and effort, and ensuring traveler safety.
Different DEMs, such as NASA DEM, SRTM, AW3D30, Sentinel-1, and ALOS, were evalu-ated in the Ras Ghareb and Zaafaran regions and El Monte Galala in the Ain Sokhna region. The results showed varying accuracy, with NASA DEM proving to be the most accurate. GPS reference elevations indicated that the RMS values were ±6.5 m for NASA DEM, ±8.8 m for SRTM, ±9.7 m for AW3D30, ±21.1 m for Sentinel-1, and ±22.3 m for ALOS. In addi-tion, elevation data from topographic maps showed that NASA DEM had the best accuracy with an RMS value of ±5.6 m. In comparison, the RMS values for the other DEMs were ±5.8 m for AW3D30, ±6.6 m for SRTM, ±17.1 m for ALOS PALSAR, and ±17.2 m for Sentinel-1. This range in accuracy is critical to consider when using DEMs for road design and other applications in these study areas.