In urban microcellular environments, fast handoff algorithms are needed to react to sudden changes in path loss characteristics that typically occur when the mobile turns around street corners. We introduce a class of fast hand-off algorithms based on a local averaging technique that removes only the fast fading component from the received signal strength. By exploiting the fact that local averaging does not substantially alter the path loss characteristics, we are able to develop an efficient and accurate numerical procedure for analyzing the performance of this new class of fast handoff algorithms. Numerical results demonstrate that the use of local averaging significantly reduces handoff delay in the presence of corner effects compared with conventional handoff algorithms. Consequently, the outage probability is reduced for the entire range of mobile speeds. Our analytical approach can be used as a tool for dimensioning fast handoff algorithms that optimize network performance in the presence of both line-of-sight and non-line-of-sight handoffs.