It differs from 20 m to one hundred m. Nearer intervals are expected if floor degree varies abruptly. The cross- sectional line needn't be usually be at proper angles to the principle line. This technique is Preferably suited for highway and railway jobs. Radial Line Strategy Correct Form and Sizing https://remingtonwsgjs.blogdal.com/32880252/how-much-you-need-to-expect-you-ll-pay-for-a-good-contour-survey