While non-separated on-street bicycle facilities have been used in the United States for many years, separated on-street bicycle facilities are becoming increasingly popular. Many state and local departments of transportation (DOTs) have recently installed such facilities to address safety concerns and promote bicycling. Numerous other DOTs are exploring the potential for additional facilities to improve and expand their bicycling networks.
On-street bicycle facilities provide exclusive travel lanes for bicyclists within the roadway. Non-separated on-street bicycle facilities are horizontally delineated from motor vehicle traffic by pavement markings, such as a painted buffer or striping. Some non-separated facilities are colored either over their entire length or through conflict areas. Separated on-street bicycle facilities are separated from motor vehicle traffic both horizontally and vertically by flexible delineators, curbs, parking lanes, or other barriers.
In recent years, there have been over 600 bicyclist fatalities annually in the United States. This sobering statistic has motivated a number of recent studies, including the recently released National Transportation Safety Board study, “Bicyclist Safety on US Roadways: Crash Risks and Countermeasures” (available at: https://www.ntsb.gov/safety/safety-studies/Documents/SS1901.pdf). That report notes that midblock crashes account for a disproportionate number of bicyclist fatalities and severe crashes, and that separated on-street bicycle facilities may reduce the likelihood of these crashes. However, there are only limited data on the safety outcomes of separated on-street bikeways in the United States.
As state DOTs and other transportation agencies expand and improve their bicycle networks, they need detailed information on anticipated safety improvements of design features for a range of sites and contexts, and the relationship between design features and the risk of midblock (non-intersection) bicycle-involved crashes and conflicts.
The objective of this research is to provide practitioners at state DOTs and other transportation agencies with data-driven guidelines for selecting context-appropriate design features for safety improvements to existing separated and non-separated on-street bicycle facilities and for the planning of new facilities. The guidelines will be based on an up-to-date, quantitative analysis of crash patterns as well as an evaluation of the roadway characteristics, land use patterns, and human factors that increase conflicts and the risk and severity of midblock crashes that involve bicyclists.