## 3 Results and Discussion  
The determination of engineering soil classification and evaluation of the allowable bearing capacity of the soil are integral parts of the soil exploration program for any civil engineering project. The AASHTO subgrade rating is the most important evaluation for route selection and design of highways and pavements. Testing, analysis, and interpretation of the collected soil samples led to the development of a collection of nine geotechnical maps, including three maps for engineering soil classification, three maps for AASHTO subgrade rating, and three maps for bearing capacity at 1.5-, 3.0-, and 4.5-m depths. The maps for the AASHTO subgrade rating are shown in Figure 6. The AASHTO subgrade rating shows diversified formation in the region, ranging from excellent (i.e., A-1) to poor (i.e., A-7). A-4 is the most prevalent subgrade rating at the depths of 1.5 and 3.0 m, while A-2-4 is dominant at the 4.5-m depth. These maps allow identifying potential merits or demerits of a route. Patches of problematic soils (i.e., A-6 and A-7) are visible in these maps. Allowable bearing capacity maps are presented in Figure 7. Allowable bearing capacity in comparatively planer areas ranges from 50 to 300 KN/m\({}^{2}\) (0.5-3 tsf), while, in hilly terrain, it increases to 1100 KN/m\({}^{2}\) (11 tsf). These maps indicate a comparatively weaker or stronger soil and contribute to the feasibility assessment of proposed engineering work. The maps for engineering classification of soil are shown in Figure 8. In addition, these maps show a diversified distribution of soil types. Fine-grained soils are dominant in the central part, while coarse-grained soils are prominent towards the edges at a shallower depth, i.e., 1.5 m. At 3.0-m depth, sandy soils overtake fine soils. Gravels are dominant at 4.5-m depth. Figure 6: (a) AASHTO Subgrade Rating at 1.5-m Depth; (b) AASHTO Subgrade Rating at 3.0-m Depth; (c) AASHTO Subgrade Rating at 4.5-m Depth. Figure 8: (**a**) Engineering Classification of Soil at 1.5-m Depth; (**b**) Engineering Classification of Soil at 3.0-m Depth; (**c**) Engineering Classification of Soil at 4.5-m Depth. Figure 7: (**a**) Allowable Bearing Capacity at 1.5-m Depth; (**b**) Allowable Bearing Capacity at 3.0-m Depth; (**c**) Allowable Bearing Capacity at 4.5-m depth. This gradual change in the gradation of soils agrees with the weathering phenomenon. Top layers are more weathered than deeper layers. This observation is also an indication of a gravity depositional deposit. The developed map is the first of its kind; it incorporates geotechnical properties of the region. This tool is ready to be used as a design aid, especially for feasibility studies, and to improve rough cost estimates. The accuracy of maps generated using the kriging interpolation technique under spatial analyst tools was verified in two layers. Initially, a geostatistical wizard was employed to validate maps. First, the cross-validation process established trends and generated autocorrelation models using all of the input data; then, it performed validation by removing each data point one by one to predict its value using all other data points. The statistical regression function (RF) and the comparison of predicted and measured values are shown in Figure 9. The average standard error for the measured and predicted values is determined as 0.145, 0.237, and 2.396 for AASHTO, bearing capacity, and Engineering Classification (USCS) maps, respectively. Root mean square was 0.031, 0.064, and 1.858 for AASHTO, bearing capacity, and USCS, respectively. To assess the accuracy of generated maps for the unseen data, another innovative technique was employed by collecting additional samples from 10 additional field survey sites and comparing the actual test results with the corresponding values in the developed maps.