Several methods exist for quantifying the quality of service provided by a roadway from a bicyclist's perspective; however, many of these models do not consider physically protected bike lanes. Of those that do, none was developed on the basis of empirical data from the United States. This gap is problematic because engineers, planners, and elected officials are increasingly looking to objective performance measures to help guide both transportation project design and funding prioritization decisions. This paper addresses this gap by presenting a cumulative logistic model to predict user comfort on protected bike lanes that was developed from data collected during in-person video surveys. The surveys were conducted in Portland, Oregon, with video footage gathered in Portland; Chicago, Illinois; and San Francisco, California. The model is for road segments only and not signalized intersections. It complements the Highway Capacity Manual 2010 level-of-service methods by providing an analysis procedure for a facility type that is not currently included in the manual. The model indicates that the type of buffer, direction of travel (one-way versus two-way), adjacent motor vehicle speed limit, and average daily motor vehicle volumes are all significant predictors of bicyclist comfort in protected bike lanes. The model predicts a mean value of A or B on a scale of A (most comfortable) to F (least comfortable) for all protected bike lane video clips that were used in the survey. Consistent with previous research findings, survey respondents report that protected bike lanes are generally more comfortable than other types of on-street infrastructure. The authors thank Mark Person of Mackenzie and Sam Thompson and Tara Goddard of Portland State University for their assistance in recruiting survey participants. Theo Petritsch of Sprinkle Consulting, Inc., provided the video clips from NCHRP Project 3-70, which were used for video quality comparison. The Department of Civil Engineering at Portland State University contributed funds used in this project. The authors acknowledge the U.S. Department of Transportation, the National Institute for Transportation and Communities, and People for Bikes for funding the related project.
Read full abstract