Sep 08, 2020 · Table 42. Idaho Base Excavation $/Mile for Road Widening with Linear Grading, ¾:1 cut slope .. 65 Table 43. Idaho Base Excavation $/Mile for Road Widening with Linear Grading, 1:1 cut slope..... 65 Table 44. Montana Base Excavation $/Mile for Road Widening with Linear Grading, ¾:1 cut slope 66 Table 45.