Trying to quantify the total length of roads within buffer zones around given sites. Some of the buffers do overlap. Following the instructions given here: SUM LENGTH OF LINES IN POLYGONS
However, I manually clipped the roads to one buffer zone to test out the spatial join and make sure it's working. With clipping manually I'm getting 86km of roads within the buffer zone. With doing all buffers at once, intersecting my road layer with the buffer zones, and doing a spatial join I'm getting 277km of roads within that buffer zone. Any thoughts as to what I'm doing wrong here? Before the spatial join I copied the data table from the intersected roadways into excel to, again, manually check the sum of the road segments and I'm getting 86km for that buffer zone still, it would seem I'm doing something wrong using the spatial join. Thanks for any help.