This study investigated how user expectations of automation performance influenced reliance and how expectations interacted with types of automation failures. Participants were assigned to a low, high, or neutral expectations group and interacted with an automated collision avoidance system that either committed errors of false detection (false alarms) or incorrect rejection (misses). Participants with high expectations had higher initial reliance than participants in the low and neutral expectations conditions. Overall, the high expectations group exhibited over-reliance behavior choosing to rely at a higher level than participants in the neutral and low conditions. Participants in the neutral condition began to appropriately adjust their behavior according to the type of automation error, however, participants in the low and high conditions did not. These findings have implications for how expectations are managed in future human-automation research.