Parking or driving in bike lines is illegal — so one Seattle bicyclist is documenting offenders on Twitter.

Cars parked in bike lanes pose a hazard to riders and are also breaking the law.

  • So one Seattle bicyclist is photographing offenders and posting them online.

Driving the news: Local cyclist Sanders Lauture recently started “Cars in Bike Lanes Seattle” on Twitter to raise awareness of a problem he says he sees regularly when biking throughout the city.

Why it matters: Parking in a bike lane is illegal, as is driving in one, unless you are in the process of making a turn.

  • It can force bicyclists to have to merge into traffic at short notice, increasing the possibility of a crash.

What they’re saying: Lauture, a software developer at Microsoft, considers the Twitter account a data collection project.

  • He started it in August, after city officials asked for public feedback on where to test new types of protected bike lanes, he told Axios.
  • “I was frustrated by always seeing cars in the same locations,” he said.
  • He’s created an interactive map of lane-blocking incidents, based on photos others have shared with the account as well as pictures he’s taken himself.

The big picture: The city wants to expand its network of bike lanes, while also building better barriers to help separate bicyclists from cars and make it harder for cars to park in the lanes.

  • Right now, the city’s protected bike lanes mostly employ plastic posts, which can be knocked down and require frequent replacement, according to the city transportation department.

The latest: A new pilot program is testing other types of barriers — including two made of concrete.

What’s next: The city will look at traffic patterns, cost and other factors when deciding where to install upgraded bike lane protections, according to the project’s webpage.

  • While that process will be data driven, city officials say, it will also take into account public feedback about where bike lanes are regularly blocked or have damaged posts.
  • So far, the pilot locations have mostly come from community suggestions, including from social media, Ethan Bergerson, a spokesperson for the Seattle Department of Transportation, told Axios.

zoom in: Lauture said he wants @carbikelanesea to be a forum for those conversations, adding that efforts to educate drivers can only do so much.

  • “There needs to be better infrastructure to prevent people from doing the wrong thing in the first place.”

Of note: The city has issued more than 500 tickets this year for people blocking trails, paths or bike lanes, at $47 each, per the transportation department.