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This value is the average width of the through lanes, in whole feet, for the primary or secondary direction of the roadway. The through lane width includes the average width of the through lanes and managed access lanes in one direction; turning lanes, painted medians, and paved shoulders are not included in the measurement. The through lane width can only change when a lane is added, removed, or when the average width changes. For paved roadways with no curbs or shoulders, measure the width between the edges of the pavement or oiled surface and divide by the total number of lanes. For paved roads with curbs, measure the width between the toes of the curb pans (exclude the gutter width) and divide by the total number of lanes. For paved roads with shoulders, left-turn lanes and/or auxiliary lanes measure the width between the painted lane dividers (or estimate this location if the striping is faded or not present) and divide by the total number of lanes. For unstriped, dirt or gravel roads, measure the width between the limits of the driving surface, excluding any drainage areas or ditches and divide by two for the primary and secondary surface width.