Long popular in northern Europe, protected bike lanes, also known as "cycle tracks" or "separated bike lanes," are seeing increased interest in the United States. One of the primary benefits of protected bike lanes is that they may provide a higher level of comfort than a standard bike lane that is only delineated by an inches-wide painted stripe. Several methods exist for quantifying the quality of service provided by a roadway for a bicyclist; however, many of these models do not consider protected bike lanes and of those that do, none are based on empirical data from the US. This is problematic as engineers, planners, and elected officials are increasingly looking to objective performance measures to help guide transportation project design and funding prioritization decisions. This thesis addresses this gap by presenting a cumulative logistic model to predict user comfort on protected bike lanes using surveys conducted in the United States. The model is for road segments only and not signalized intersections. It is developed from the results of in-person video surveys conducted in Portland, Oregon. The survey was completed by 221 individuals who viewed 20 video clips each. The model is validated using 3,230 responses to a survey of those who have ridden on protected bike lanes in multiple cities around the US. A cumulative logistic model is used because it predicts the distribution of ratings, providing a clearer picture of a facility's performance than a mean value produced by a simple linear model. The resulting model indicates that buffer type, one-way vs. two-way travel, motor vehicle speed, and motor vehicle average daily traffic volumes are all significant predictors of bicyclist comfort in protected bike lanes. Survey results also show that protected bike lanes are generally more comfortable than other types of on-street infrastructure, consistent with previous research findings.