Hey OP, turns out HUB already made some questions, and the answer is even weirder than one would imagine: https://mastodon.social/@anthonyfloyd/111774518967683022

These speed bumps were installed on the section of the greenway between 7th and 8th Ave, by the Broadway Subway team. That section of the greenway is officially closed to people on bikes, although the signage communicating that has been quite poor. Apparently the Project received complaints about cycling on that stretch.

HUB reached out to the Project team when we were notified about the installation of the speedbumps for clarification. The clarifications were:

1. This section is indeed closed to people on bikes. People on bikes should detour to Yew or Cypress St
2. This section is not closed to pedestrians
3. Better signage will be installed

We pointed out how odd this was, as well as calling out the speedbumps as being problematic for ppl w/ mobility devices/challenges.

At any rate, this is a stretch of the greenway that goes nowhere because the greenway between 8th and B/Way is completely closed. 8th Ave itself is being used as a truck route for the project, so having fewer people around there in general (whether or on bike or not) makes sense from a construction safety perspective.

In the end, I think we'd prefer that the closure was better indicated (gated? fenced?) the detour better signed, and that any measures were equitable for all people.

The intention is for it to be inaccessible. The Broadway Project considers that stretch closed for construction purposes. I don't understand why they consider it closed for people on bikes but not pedestrians.

I do think that they hoped that people on bikes just wouldn't ride there because it goes nowhere, so they didn't put much effort into visible "closing" it. That seems to reflect a misunderstanding of human nature. /shrug

So in the end this is overall lazy thinking from the Subway Project team, pending a better resolution.