Mineta Transportation Institute at San Jose conducted a study on bicycling network to identify the key factors to improve bike commuting by so-called “level two” cyclists: those who will ride if car traffic is minimal.
The main determinant of biking is a low-stress, well-connected and relatively direct route. This research has highlighted the importance of intersection approaches and street crossings in network connectivity. A major achievement has been developing criteria for crossing stress and a way of integrating intersection stress with the stress on a link.
The researcher proposes a set of criteria by which road segments can be classified into four levels of traffic stress (LTS). LTS 1 is suitable for children; LTS 2, based on Dutch bikeway design criteria, represents the traffic stress that most adults will tolerate; LTS 3 and 4 represent greater levels of stress.
The study then mapped every street in San Jose according to LTS and they found that only about five percent of shorter (under six miles) work trips in San Jose could currently be accomplished on low-stress (levels one and two) streets, but this figure would almost triple if improvements in strategically placed segments that provide low-stress connectivity across barriers were implemented.