When a cyclist dies on the streets of San Francisco, the tragedy is often memorialized by a ghost bike. You've likely seen the all-white bikes chained to various poles or signs near the site of a deadly crash. However, you may not have, as it is city policy to remove the bikes after two weeks. According to ABC 7, families of slain cyclists want that to change.

Julie Mitchell spoke with the channel about her son's ghost bike. Dylan Mitchell died three years ago after a collision with a garbage truck, and his family placed the memorial for him close to where he was hit. "People would stop and pay their respects, they would read it, people would slow down to see it," Mitchell told ABC 7. "It was making an impact. It was more than just a memorial to us, it was a powerful tool, I feel."

That bike, like so many others, was quickly dismantled and taken away by city officials.

"Very disrespectful," Mitchell said of its removal. "Like throwing my son in the garbage."

Things could change, however, if Devon Warner gets her way. Warner has launched a petition aimed at the city's bicycle advisory committee with the goal of allowing current bikes to remain in place for a year — assuming, of course, their placement don't cause any public safety issues — until a new policy can be reached. She also intends to deliver a resolution to the same committee requesting that said new policy allow ghost bikes to remain in place longer than the currently permitted two weeks.

"In San Francisco, the Dept. of Public Works removes the locks on these Ghost Bikes and the bikes are trashed," reads the petition. "This is deeply disturbing to the families and friends who mourn the fallen and to the bike riding community at large. We ask the Bicycle Advisory Committee to put forth a resolution to the SF Supervisors, asking for an immediate moratorium on the removal of Ghost Bikes for one year, during which time the Committee may negotiate with City Departments for an ordinance allowing the placement of Ghost Bikes and/or other memorials."

Warner wrote on Facebook that she intends to deliver her resolution to City Hall this Monday.

Although it is unclear how the city will respond, Mayor Ed Lee recently announced several initiatives with the goal of improving pedestrian and cyclist safety. As such, Warner might be catching City Hall at a good time, and ghost bikes may soon become more of a lasting presence on our streets.

Related: Video: SFPD Officer Crashes Car Into Cyclist In Bike Lane On Bike To Work Day