The challenge of communicating bicycle comfort level on maps

By Robbie Webber

Although some bicyclists are willing to ride on any road and under any conditions to get to their destination, the vast majority do not feel comfortable mixing with higher speed traffic and watching out for turning cars. A 2012 Mineta Transportation Institute study examined the stress level of riding on different streets in San Jose, CA, to determine a bicycle “comfort index.”

Bike maps should reflect the conditions bicyclists might face, not just whether a bike lane exists on the road. That is the premise of a new bike map in Austin, TX. After all, a bike lane on a four-lane arterial with left-turn pockets, trucks, and a 45 MPH speed limit feels very different from a bike lane on a two-lane road where drivers generally travel at 20-25 MPH, even if the volume of traffic is fairly high on the narrower street.

Austin is not the only city to attempt to rate their street network by bicyclist comfort. However, they are one of the first to attempt to represent the “feel” of the street on a map. But what feels comfortable for one bicyclist may intimidate someone else. Trying to find an objective way to rate and represent biking conditions can be a challenge.

Atlantic Cities recently highlighted the new Austin bike map, which tries to represent the feel of the bicycling experience on various routes through the city. Using Roger Geller’s typology of bicyclists and aiming to appeal to the 60 percent of the population that Geller identifies as “interested but concerned,” the map uses an intuitive color code. Green is used for separated paths, bright and dark blue for streets with a high bicycle comfort level, and yellow through red for streets only the most confident bicyclists will likely want to use.  The color code allows the map’s users to easily see both comfortable routes and gaps where they will face more challenging conditions.

Two scales have been in use for years. The Bicycle Compatibility Index, or BCI, rates urban and suburban streets on a number of factors such as width and number of lanes, speed limit and 85th percentile speed, amount of truck traffic, turning movements, and type and turnover of parking. It was developed by FHWA in 1998 in part by showing video of riding conditions to bicyclists and asking them to rate the suitability of the roadway.

The Bicycle Level of Service, or BLOS, uses some of the same factors, but also includes pavement condition since bicyclists are considerably more sensitive to potholes and cracked pavement than motorists. It was developed at about the same time as the BCI, but is based on research conducted by Sprinkle Consulting Engineers and the Transportation Research Board in 1997. Instead of video of riding conditions, the BLOS used actual bicyclists to test varying types of roadways.

The inputs needed for both of these metrics may not be available for many of the local roadways that bicyclists use on a regular basis, so city officials trying to offer preferred riding conditions may need to rely on known bicycle routes instead of objective measures. In addition, neither the BCI nor BLOS has inputs for evaluating new facilities such as buffered bike lanes or cycle tracks. Even a separate path may not be comfortable to bicyclists if there are multiple driveway crossings or if the pathway is congested with more bicyclists and pedestrians than the path is designed to accommodate.

Although both the BCI and BLOS are excellent efforts to rate street facilities for bicycling, in order for maps to be more useful to those who would like to bike for transportation but are part of the “interested but concerned” category, local knowledge of routes may need to be combined with a stress-level rating system.

Robbie Webber is a Senior Associate at SSTI.