For every dollar spent to build new separated bike lanes, cities could save as much as $24 thanks to lower health care costs and less pollution and traffic, according to a new study from researchers in New Zealand," according to Adele Peters.
However, small investments in bike infrastructure can actually be a setback for biking's mode share. According to Peters, "[in] cities dominated by cars, a small increase in cycling tends to lead to more biking injuries and deaths, making other people more afraid to ride. The way to overcome that problem, the researchers found, is to make a bigger commitment to better bike lanes."
Peters briefly describes the ground this study breaks as it joins a growing body of research about the many benefits of bike infrastructure: "this study may be the first to look at how different types of bike infrastructure investments pay cities back later."