For more context: https://www.citylab.com/transportation/2014/07/transit-proje... https://www.sfcta.org/projects/van-ness-improvement-project
From https://www.sfexaminer.com/news/sf-transit-board-approves-ca...:
> Better Market Street will be implemented in three phases: Market from Fifth to Eighth streets is phase 1, Market from Fifth to Second streets is phase 2, and Market from Van Ness to Octavia Boulevard will comprise phase 3.
> The second phase will also include the construction of a loop in the Financial District for the F-Market & Wharves historic streetcar...
> Phase 1 is scheduled to stretch at least until 2022, according to the project’s website. The construction of the streetcar loop is expected in 2023, and future phases of the project are dependent on identifying funding
So 1/3 of this project is projected to be finished by 2022. And the other two portions of market street don't even have funding or a timeline yet. We will be lucky if it's finished by 2026 (no delays, no recession puts funding in jeopardy, etc).
By the time everything is done, it may be _20_ _years_ to build protected lanes. In the meantime, we have sharrows and intermix with taxis.
The situation I'm picturing where it could take a few years is if the bike lanes are raised up to the same level as the sidewalk. Which can take a long time because it means moving existing curbs, which means moving catchbasins (curbs direct water flow) and often light posts (should be near edge of road for accessibility purposes - maintaining clear walking path, having push buttons and audible signals at edge of street). Doing either or both of these things means stuff is getting moved around underground, and underground is a very busy place (sewer, water, natural gas, buried electrical, signal infrastructure, old foundations, ... And all these are at different depths, with different separation requirements, severally limiting what can go where). And add in a busy location like Market Street, and maintaining access all the time, and probably limiting working hours to minimize impact on residents/businesses. The time would add up fast.
There's no upper limit to how long you can take to do something.
Lower limits, sure, but no upper ones.