How
effective are bike lanes at enticing people to ride? Portland State
University professor Jennifer Dill has been looking into that question
for more than a year, and her research is starting to get some
attention. Using GPS trackers to map more than 1,700 bike trips, Dill
found that about half of all bike travel occurs on dedicated
infrastructure like bike lanes or bike boulevards, even though such
routes comprise only eight percent of Portland’s street network.

Dill
also conducted surveys about who rides most often and why people choose
to bike or drive. She concludes that bike riding won’t expand far
beyond a core demographic of young men unless perceptions of safety
change, reports the Portland Tribune:

According to Dill, most regular bicyclists are young men. This means
that if the city wants to substantially increase the number of people
riding bikes on a regular basis, it needs to reach out to young women
and older people. And, Dill said, that is what public spending on bike
infrastructure can accomplish.

All this may come across as confirmation of common sense (Portland DOT has based its bike network strategy
on similar surveys), but the notion that dedicated bike routes make
cyclists safer is not universally accepted. Proponents of "vehicular
cycling" reject bike infrastructure forcefully,
claiming that biking with traffic reduces collisions. They wield
considerable influence over design standards at the federal level, and
in Portland they have consistently opposed steps intended by the city to improve safety and boost bicycle mode share.

Dill’s preliminary research [PDF]
adds to the evidence that dedicated bike infrastructure matters.
Without a bike network that makes everyone feel safer — men and women,
children and seniors, veteran and inexperienced riders — it’s hard to
imagine that American cyclists will ever enjoy the safety in numbers that cities like Copenhagen have managed to produce.

Graphic: Jennifer Dill