Latest Highland Park Way SW design maintains bike lane protection up to the W Marginal Way intersection
SDOT is standing by its reworked design for a new downhill protected bike lane on Highland Park Way SW. But the biggest improvement should be to the safety of people inside cars. The project is planned for construction as soon as February 2027," according to the project webpage.
Highland Park Way is a long, steep hill through a greenbelt has no major intersections the entire way from SW Holden Street at the top to W Marginal Way SW at the bottom where it meets with the Duwamish Trail. Though the downhill direction is fed by only one lane at a time, it currently widens out to two lanes, a design that encourages speeding and increases danger without improving traffic throughput. The addition of a downhill bike lane should make it much more comfortable to bike downhill, but it should also make the existing path more comfortable for uphill biking and two-way walking since there should be fewer fast downhill riders on it.
Perhaps more importantly, the single-lane design for the downhill section of roadway should reduce the out of control speeding problem on this street where the AVERAGE speed is 41 mph in a 25 mph zone. 16 over the limit as an average speed is wild, and the scale of the issue makes it clear that only a redesign of the street can address such a widespread flaunting of the law. So that's what SDOT is planning to do. It is a fact that having too many lanes encourages speeding. They make the roadway feel to the average driver like going faster is appropriate regardless of the speed limit.
The result of rampant speeding can be tragic. In the five years from 2021 through 2025, one person was seriously injured while walking on this stretch of road and two people biking were involved in collisions with people driving. Meanwhile, there were twenty-four injury collisions between motor vehicles, and two people were seriously injured. Crash patterns include recurring rear-end and angle collisions, especially near the W Marginal Way SW intersection," wrote the SDOT project team. Drivers have also left the road, crossed the centerline, sideswiped vehicles, and struck a person biking."
Drivers have less stopping power when going downhill, and the long segment between intersection breaks allows people to easily exceed the speed limit by a lot. Though thankfully nobody was killed on this section of the road in those five years, it has all the conditions needed for a major tragedy. A lot of the discourse around this project has been of the bikes vs cars" variety, and I really hope people can see past such a short-sighted view of what's at stake here.
The single lane downhill will slow average speeds, and hopefully it slows them enough to dramatically improve safety for everyone. At the same time, people biking downhill will have a space to do so where they are not either mixing with 41 mph traffic or squeezing onto a single sidewalk with two-way walking and biking.
It's not a perfect project for bikes. Buses will mix with the bike lane for two stops, and uphill riders still need to use the shared-use path/sidewalk since the project is preserving the dual uphill general purpose lanes. However, the path will be repaved and widened. I wonder if SDOT could label the right uphill general purpose lane for slow moving vehicles only like on mountain passes as a way to reduce the speeding problem in that direction as well.
Since most people on bikes will be headed to and from the Duwamish Trail on the opposite corner of the intersection with W Marginal Way, a new bike crossing will be added. Hopefully, the team adds clear signage so uphill riders know to use the crossing and then take the path since this is an unusual set-up that may not be immediately obvious to a new user.
More design concept images from the project webpage:
