Customer loyalty is commonly used across sectors to measure a provider's effectiveness in satisfying the needs of its market. According to the most recent Chicago, Illinois, Transit Authority (CTA) customer satisfaction survey of 2008, customer loyalty with the CTA bus had increased significantly over time. This paper looks at the key factors (service characteristics, trip attributes, and individual characteristics) associated with customer loyalty in 2008. The analysis used two methods: a quadrant analysis to highlight aspects of service in most need of improvement and a multivariate regression that attempted to explain the variance in the dependent variable bus loyalty. This variable was measured as an index of three one-to-five scale variables: how satisfied the customer was, how likely he or she was to continue riding CTA, and how likely he or she was to recommend the service to someone else. Findings provided evidence of specific ways in which the agency could increase bus loyalty in a targeted and informed manner.