Denny Way Bike Lane: Safe Micromobility Corridor

## CONTEXT Denny Way is a major east‑west arterial in Seattle, connecting the waterfront to Capitol Hill and carrying over 20,000 vehicles daily. It serves as a critical link for commuters, but its current design prioritizes high‑speed car traffic with narrow sidewalks and no dedicated cycling infrastructure. The Seattle Department of Transportation’s (SDOT) 2014 Bicycle Master Plan identified Denny as a “high‑priority” corridor for a protected bike lane, yet implementation has stalled due to political opposition and funding constraints. Meanwhile, micromobility use—e‑scooters, e‑bikes, and traditional bicycles—has surged in Seattle, with Lime and other operators reporting over 1 million trips annually in the downtown area alone. The situation is complicated by the fact that Denny’s sidewalks are unusually wide in many segments (up to 15 feet), a legacy of its history as a streetcar boulevard. This width creates an opportunity to reallocate space without reducing vehicle lanes, but it also invites conflict: pedestrians, scooters, and cyclists currently jostle for space, while car drivers honk at riders who take the travel lane. The question is whether Seattle can finally act on its stated climate and safety goals by building a protected lane on Denny. The answer, based on comparable projects in other U.S. cities, is yes—but only with a clear design, dedicated funding, and community buy‑in. ## PROBLEM The core problem is a dangerous mismatch between infrastructure and user behavior. Denny Way has no bike lane, forcing riders of e‑scooters, e‑bikes, and bicycles to choose between two unsafe options: riding in a travel lane with fast‑moving cars, or riding on the sidewalk with pedestrians. The first option leads to frequent close calls and collisions—Seattle recorded 87 bike‑involved crashes on Denny between 2015 and 2020, with three fatalities. The second option creates pedestrian hazards: a 2022 SDOT study found that 34% of pedestrian‑micromobility conflicts in the downtown core occurred on sidewalks adjacent to roads without bike lanes. The cost of inaction is measurable: emergency room visits for e‑scooter injuries in Seattle rose 220% from 2018 to 2023, and pedestrian injuries from sidewalk collisions increased 15% year‑over‑year. Beyond safety, the lack of infrastructure suppresses mode shift. Surveys by the Cascade Bicycle Club show that 60% of Seattle residents would bike or scoot more if protected lanes existed on major arterials like Denny. Without action, car dependency remains entrenched, contradicting the city’s goal of reducing single‑occupancy vehicle trips by 30% by 2030. The problem is not unique to Seattle—similar corridors in Portland, San Francisco, and New York faced the same dilemma before implementing protected lanes. ## PROPOSED SOLUTION The proposed solution is to convert a portion of Denny Way’s excess sidewalk space into a two‑way protected bike lane, separated from both pedestrians and cars by a physical barrier (e.g., concrete curbs or flexible bollards). The design would follow SDOT’s “cycle track” standards used on 2nd Avenue and Dexter Avenue, with a minimum width of 8 feet to accommodate two‑way micromobility traffic. Implementation would occur in phases: first, a pilot segment from Westlake Avenue to Broadway (1.2 miles), funded by a mix of the city’s Move Seattle Levy and a state grant from the Washington Transportation Improvement Board. Rejected alternatives include a painted bike lane (deemed unsafe due to high traffic speeds and frequent doorings) and a shared‑use path on the sidewalk (rejected because it would still force pedestrians and riders into conflict). The decision process follows the SPADE framework: the Situation is clear (dangerous corridor), the Decision is to build a protected lane, the Action is to reallocate 6 feet of sidewalk width, the Process involves a 90‑day community engagement period with pop‑up demonstrations, and the Execution would be contracted to a local engineering firm with a 12‑month construction timeline. Comparable proposals in other cities—such as New York’s 9th Avenue protected bike lane—used similar sidewalk‑reallocation strategies and were completed on time and under budget. ## EXPECTED IMPACT If implemented, the Denny Way protected bike lane is expected to produce three measurable outcomes. First, a 40–50% reduction in micromobility‑related injuries on the corridor, based on data from Seattle’s 2nd Avenue protected lane, which saw a 44% drop in cyclist injuries within two years of installation. Second, a 15–20% increase in bike and scooter mode share on Denny, consistent with the mode shift observed after the Dexter Avenue lane opened (18% increase in bicycle volumes). Third, a 25% reduction in pedestrian‑micromobility conflicts on adjacent sidewalks, as riders move off the sidewalk and into the dedicated lane. The primary beneficiaries are micromobility users (estimated 3,000 daily trips on Denny by 2027), pedestrians (who regain safe sidewalk space), and the broader public (through reduced emissions and traffic congestion). The scope is corridor‑specific but will serve as a proof‑of‑concept for similar arterials like Aurora Avenue and Rainier Avenue. Metrics will be tracked via SDOT’s annual bike counts, crash reports, and a pre‑/post‑survey of user satisfaction. The expected cost is $4–6 million for the pilot segment, with a benefit‑cost ratio of 3:1 when accounting for safety savings, health benefits, and reduced car travel. Comparable projects in Portland (SE Hawthorne) and San Francisco (Market Street) achieved similar or better returns. ## DECISION LENS | | If this passes | If this doesn't pass | | --- | --- | --- | | What will happen | Protected lane built; injuries drop; mode shift begins; pedestrian conflicts decrease; city gains a replicable model. | Status quo continues; injuries and conflicts persist; mode shift stalls; public frustration grows; city misses climate targets. | | What won't happen | Car lane capacity will not be reduced; parking loss will be minimal (only on one side); no major traffic diversion. | The opportunity to use sidewalk space for a low‑cost lane will be lost; future funding may be reallocated; political momentum for bike infrastructure weakens. | ## PRECEDENTS EXAMPLE: Seattle, WA — What: Converted a parking lane and part of the sidewalk into a two‑way protected bike lane on 2nd Avenue from Pike to Yesler. — Outcome: Cyclist injuries decreased 44% in two years; bicycle volumes increased 35%; pedestrian‑bike conflicts on sidewalks dropped 60%. — Outcome: Cyclist injuries decreased 44% in two years; bicycle volumes increased 35%; pedestrian‑bike conflicts on sidewalks dropped 60%. EXAMPLE: New York, NY — What: Reallocated 8 feet of sidewalk and parking space to create a protected bike lane on 9th Avenue from 14th to 23rd Streets. — Outcome: Cyclist injuries fell 58%; commercial corridor retail sales increased 49% (due to improved pedestrian environment); travel times for cars remained stable. — Outcome: Cyclist injuries fell 58%; commercial corridor retail sales increased 49% (due to improved pedestrian environment); travel times for cars remained stable. EXAMPLE: Copenhagen, Denmark — What: Converted wide sidewalks on Nørrebrogade into a raised cycle track separated by a curb, with pedestrian space retained. — Outcome: Bicycle mode share on the corridor rose from 35% to 55%; pedestrian injuries from bike collisions dropped 80%; car traffic volumes decreased 20%. — Outcome: Bicycle mode share on the corridor rose from 35% to 55%; pedestrian injuries from bike collisions dropped 80%; car traffic volumes decreased 20%.

August 09, 2026