bikingshearer 

I am not a fan of physical separation barriers on a street. Everything about the pictured set-up in Walnut Creek looks good to me, except the pylons. As DiabloScott points out, they make street sweeping impossible, meaning more flat tires.

Berkeley has installed major revisions to Milvia Street through downtown, including physical curbs between car and bike lanes for number of blocks. I don't like them. They remove all options for maneuvering when necessary, such as for broken glass or pother debris on the bike lane, when someone parks across the sidewalk and bike lane or otherwise parks in/blocks the bike lane. And yes, I've already seen this - the average DoorDash or Uber driver is not the least bit shy about blocking traffic lanes whenever it suits their purposes, and to hell with everyone else. I've had an unpleasant encounter with travelling auto detailer who thought the bike lane at a driveway cut was the perfect place to park while detailing a car, thus completely bottling up bike traffic. The curbs also cut down on - and sometimes eliminate completely - my ability to take a lane at an intersection to avoid being in the position to be "right crossed" by an inattentive driver. Put simply, the curbs cut down on my options for dealing with suboptimal and/or emergency situations, and I actively dislike that.

The Walnut Creek pylons are better than Berkeley's curbs, but they are still an obstacle to be considered in split-second decisions and definitely will make the bike lane more glass- and garbage-clogged. Not a good thing.

Perhaps better physical barrier would be rumble strips along the painted line closet to the auto traffic. The give an audible and physical clue to wandering drivers but still allow emergency bike maneuvering.