The paper describes the technical challenges in implementing cluster based congestion management systems. The study attempts to generalize the market based zonal pricing method being used in the energy market in California for alleviating congestion in the system. The practical implementation of the cluster-based systems consists of two steps: (1) aggregation of individual nodes into clusters and (2) computation of cluster-wide prices. The resulting clusters and prices determine an operating condition that is at the optimum with respect to some predened objective function while keeping the power transfer across cluster interfaces within the acceptable limits. We illustrate two possible ways of aggregating nodes into clusters and compare the resulting solutions.