["Transactions in GIS, Volume 30, Issue 5, August 2026. ", "\nABSTRACT\nIn sampling‐based process, sample size is always a debated topic. To assess positional accuracy using points, there are several studies and standards that determine what sample size should be used. However, for positional control using lines, there is no knowledge of a study that indicates the sample size. Therefore, this study proposed a method to determine this sample size, based on Monte Carlo Simulation. A database composed of 46,460 km of roads from 10 provinces in Spain was used, and area sizes from 1 to 250 km2 were analyzed. Comparison between samples and population was performed using the Kolmogorov–Smirnov test. This proposal took into account the spatial distribution pattern of the sample, and the result is presented in the form of an equation that provides the sample size based on the size of the area being assessed and yielded a coefficient of determination (R2) of 0.9252.\n"]