The N 130th Street Buffered Bike Lane in Seattle, completed in June 2010, runs along a .32 mile segment from Linden Ave. N to Greenwood Ave. N. The project grew out of a pedestrian project to improve a mid-block, uncontrolled marked crosswalk at North Park Avenue N. Before the reconfiguration, N 130th Street was a three-plus lane arterial street with a history of speeding. N 130th Street had an Average Daily Traffic (ADT) of 11,353 and a posted speed limit of 30 MPH. 85th percentile speeds along the corridor were 38 – 39 MPH before the re-channelization. The city wanted to reduce the number of lanes for pedestrians to cross at this location, which serves a Community Center and park on the north side of the street and apartments and single family homes on the south side. The neighborhood also has a high senior citizen population.
The reconfiguration of N 130th St. initially called only for the installation of a raised median midway through the pedestrian crossing. In coordination with these improvements and the Bicycle Master Plan, the city decided to implement buffered bike lanes as part of the re-design. The city first looked into creating one bike lane in each direction, but a center left turn lane did not leave enough room for installation. Left turn movements along the corridor were minimal since there are no intersecting streets on the north side of N 130th Street and all the intersecting streets on the south side are non-arterial. The city decided to reduce the number of travel lanes to one in each direction and to create a buffer that reduces the width of the vehicle travel lane to discourage speeding.
As part of the N 130th Street buffered bike lane project, video detection was installed for the westbound approach at Greenwood Ave N and N 130 St. After shifting the existing lane markings to add the bike lanes, existing detection loops on this approach were no longer in the correct locations. Video detection was chosen because it was cost-effective and cheaper to install than cutting loops for three vehicles lanes and one bike lane. The pavement was also in subpar condition for cutting new loop detectors. The other three sections of the intersection continue to function using loop detection.
N 130th Street Buffered Bike Lane Project Plans
Buffered Bike Lane Greenwood Ave N and N 130 St Plans
Video Detection Installation Plans