one embodiment of the present invention provides a system that facilitates routing nets between cells in a circuit layout . during operation , the system receives a circuit design to be routed , wherein the circuit design includes multiple circuit blocks that have been placed at specific locations within the circuit layout . next , the system determines estimated lengths for nets that couple these circuit blocks together . the system then calculates the delay for the nets that couple the circuit blocks using a class one rule . if the delay in a given net is greater than a specified delay , the system inserts a virtual repeater into the given net to decrease the delay .