A set of nets in an integrated circuit design, having a timing margin and traverse routing tiles, are identified. The set of nets are assigned a utilization metric based on the traversed routing tiles. A set of sparse nets are determined from the set of nets, based on the utilization metric of each net in the set of sparse nets. One or more target nets are selected from the set of sparse nets, based on the timing margin of the target nets. The target nets may be modified.