Brought my tape measure to SF today. Gonna measure me some bike lane widths.

I will be ignoring painted lines, since drivers ignore them too. All measurements will be between vertical elements, such as curbs and soft-hit posts.

First up: Market SW at Hyde. Lots of posts here, but since it's 8'7" wide it still gets occasional drivers.

Market SW at Hayes, with more and different kinds of posts. A little wider, 8'10". Also gets occasional drivers.

17th W at Church. 6'6" at the entrance, 8'10" past there. Apparently some school parents use this as a pickup lane.

Duboce W at Church. 5'11" at the posts, 6'1" at the island. No drivers use this.

Scott at Fell. With just the bulb-out, some drivers would sneak through. Now that posts have been added I haven't seen any sneakers. 7'7" NB, 6'10" SB.

Fell from Scott to Baker: 7'3". No drivers use the protected part. Some do sneak into the unprotected parts.

JFK at Kezar: 7'. Since the posts went up ( thanks @SFMTrA!), no drivers use this. However the problem here was not blockers, it was people cutting the corner at high speed. The posts fix that too.

Oak between Baker and Scott. The protected parts are 7'3" wide, and work great. As with Fell, some drivers still sneak in on the unprotected parts.

Market NE at Octavia: 5'7". The island was added to stop drivers from making the illegal right turn and killing bicyclists. I don't think it worked until the big gun was rolled out: photo enforcement. And that apparently required a change in state law.

Division SE at Bryant: 8'1". I've seen drivers snaking through here but it's not common.

7th NW at Folsom: a big fat 9'11". I see drivers using this pretty often, to access the parking on the right. They are supposed to drive across the island - see the lowered curbs? - but they don't.

8th SE at Market: 5'7". No drivers go through here. Lots of drivers use the tan refuge zone just ahead, by backing into it. Needs one or two more posts, on the downstream side.

Folsom NE at 7th: 10'. Lots of drivers think this is a right-turn slip lane.

My favorite, Folsom NE between 5th and 4th. When Folsom gets backed up there's a steady stream of drivers in the bike lane. Some go around on the right, through the 13'8" gap (six while I composed this tweet). Others just zoom straight through the gate, which is only 7' wide!

Folsom NE at Essex. This was a de-facto right turn lane before the posts went up. Now it's fine. With a width of 7'1", no drivers try to use it.

The next block is still a madhouse though.

That's all for today. Now comes sandwich time. – bei Woodlands Market

Aww yeah.

Addendum: I made a table with the lanes sorted by width. Aside from the Folsom Street slalom gate outlier, it looks like the cut-off point for drivers being comfortable driving in a bike lane is: around seven and a half or eight feet wide.

All of these lanes feel fine for me to ride in. The narrower ones do not have room for passing, which is a concern.

Yesterday I was saying the maximum bike lane width should be 6'. Based on this data I'll raise that to 7'. Past that there's too much risk of abuse by drivers.

Looking back at this thread a day later, I see that I unintentionally identified three spots where an easy @SFMTrA-style installation could significantly improve a bike lane.

First, 17th WB between Church and Sanchez. The entrance to this bike lane at Church is narrow and excludes cars, but there's a driveway mid-block and drivers sneak in there. Adding one post to narrow that too would help keep them out of the rest of the bike lane.

Second, Folsom NE at 7th. This is where some drivers think the bike lane is a right-turn slip lane. Adding one post on the line between the bike lane and the buffer zone should fix the mis-perception.

Third, the slalom gate on Folsom NE between 5th and 4th. While a few drivers do zoom straight through the gate, by far the majority swing around it on the right. Adding one post on the right side of the buffer zone would narrow the right-side gap and discourage this.

In each of these three spots, adding a single soft-hit post would perceptually narrow the gap. It's not physical exclusion, it would merely make most drivers change their assessment from "I could probably squeeze through there" to "better not try, might scratch the paint".

Reviving this thread because I have a few more bike lane measurements to add. First, the bolt-on bus platforms on Telegraph in Oakland. The first part is 6'7" from curb to platform, but the ramp is only 4'8". The narrower part up ahead is 5'6" wide.

Surprisingly, I have seen these blocked twice. The first was a guy in a pickup who backed in, two wheels on the platform and two in the bike lane. The second, just today, was a guy in a mobility scooter waiting for the bus on the raised crossing area instead of on the platform.

More common is a bike lane blocker just downstream of the platform blocking the exit, so you have to jump up onto the platform or curb. Some soft-hit posts downstream of every boarding platform would fix this, and should be a standard part of the installation.

Back in SF, here is San Jose between Milton and St. Mary's. 10'5" from post to post. When San Jose is busy, drivers sneak through in the bike lane. One did it just now!

Starting a block further ahead on San Jose, the K-rail section is 11'3" wide. Drivers go through here very rarely but yeah, it does happen.

The brand-new protected lane on Valencia! The lead-in parking-protected part is 9'4" wide, while at the school boarding islands it narrows to 5'6" NB / 5'3" SB.

As with all parking-protected bike lanes, it takes a while for drivers to get the message.

Also brand-new: Howard. At 6th it's 11'7" wide.

At Howard and 7th there's an unbuffered pocket lane, haven't seen one of those before. It's 6'4" wide.

At Howard and 9th there's another post-protected unbuffered pocket lane. This one has more posts and full-green paint. Same width.

Polk counter-flow lane: 6'5" wide.

This boarding island on North Point at Polk is, what, a year old? At 5' wide no one drives through, but people do block the exit pretty often.

And lunchtime. A San Francisco classic.

Summary of today's measurements, in the traditional P4-green phosphor. The line marks the 7' width that I claim keeps drivers out.

Prediction: the new Valencia and Howard parking-protected bike lanes are too wide and will have persistent problems with drivers blocking them.

If this prediction for Valencia and Howard comes true, my suggested remedy is the same as before: add a soft-hit post at each entrance to narrow the opening to 7'.

Also a new suggestion from today's observations: always place some soft-hit posts downstream of boarding islands.

Polk was recently reconfigured with a bunch of new bike infrastructure. There's plain white stripe bike lanes, full green bike lanes, dotted-green mixing zones, a few lowly sharrows. But what's important for this thread is the post-protected bike lanes.

The main stretch of post-protected lanes is the eight blocks northbound/uphill from Turk to Pine. From curb to post these measure 8'5". Guess what? Drivers park in them. They are too wide. Adding a post at each entrance to narrow the opening to 7' would help.

There are also a few post-protected blocks southbound/downhill. I didn't measure those but they looked a little narrower. Didn't stop this guy tho. ¯\\_(ツ)_/¯

Oh I forgot to mention one really great new piece of bike infrastructure on Polk: Leading Bicycle Interval signal phases! At lots of intersections!

The 2nd St. bike lanes are finally getting finished after like half a year of delay. Southbound between Howard and Folsom even got some posts! Some bike twitter folks were alarmed that the posts were placed on the green paint instead of the white line, so I decided to measure.

The curb to post distance is 6'8". Compare to the bike lane width at the bus island, which is 5'10'. Conclusion: ignore the paint, 6'8" is fine.

Of course the unprotected part between the bus island and the posts still gets used as an Uber drop-off zone. One just now while I was measuring. Why not posts along the whole block?

Also, the Howard St. protected lane is progressing east. Here's the new start, at 4th. Curb to posts in this initial narrow section: 6'6".

27th Street in Oakland got a block and a half of new protected bike lane, as mitigation for development on the Biff's site. K71 bollards, too, much heftier than the usual posts. Width is 9'6", and 8'1" at the purple zones (assuming the missing bollards there get installed).

This is wider than I like. Will not be surprised to see drivers sneaking in through the open ends "just for a minute".

In SF, Market SW-bound at Valencia - i.e. "the jughandle" - got post protection this week. This block has been a hot spot for bike lane parking, especially at the chicken store, so yay posts. However...

At the jughandle itself, the new posts narrow the through-lane to only 2'11"! Yow! That is not ok.

A lot of people saw this and fixated on the posts being installed on the green paint. My position is that the paint is irrelevant, the width is what matters.

On 2nd Street, SFMTA also installed posts on green paint, and people also freaked out. I measured the curb to post width there and it was 6'8", which is fine. The width here is not fine.

Now it's easy to see how this happened. If you look at the distance shot a couple of tweets back, you'll see that the posts start in the middle of the buffer zone, right where they should be. But then something weird happens...

The buffer zone disappears! And then reappears after the jughandle. The line of posts stays perfectly straight, but the edge of the bike lane zig-zags to be wider at the jughandle.

It's clear to me that this is not an erroneous install, it's what they meant to do.

As for how to fix it, I would not be surprised if SFMTA shrinks or fully removes the jughandle island.

More bike lane measurements today! First, the dead end of Tiffany at Duncan and Valencia. Both directions are 5'10" wide. No one drives through, well except motorcycles which happened while I was measuring. Lots of drivers illegally turn into Duncan though.

Second, a re-visit of 17th westbound at Church. Previous visit this was posts only, and was 6'6" at the entrance and 8'10" after that. Now there are actual concrete islands, yay! And things are slightly narrower: 6'4" at the entrance, 8'2" at the islands.

Third, the Market and Valencia jughandle. Last week this got posts, yay! which narrowed the through-lane to only 2'11", booooo! But @sfmta_muni responded quickly and moved the posts out to the edge of the painted lane. Now the through lane is 3'8" wide.

3'8" is better than 2'11" but it's still the narrowest SF bike lane I've measured. The next one up is North Point at Polk, at 5' wide it's 16 inches wider than this. 3'8" is pretty bad. It's too narrow for some cargo bikes, mobility tricycles, and pedicabs.

When the lane was paint-only it was still too narrow but that didn't matter because you could ride to the left if you were worried about hitting the island. Now you can't, you have to thread the needle. I'm glad the posts were added but I think the width will still be a problem.

Here's an idea for @sfmta_muni: just remove the two posts right at the jughandle island. They are not needed to exclude drivers there, because island, and they endanger cyclists. Nuke 'em!

From @JeffSpeckAICP's book "Walkable City Rules" - he makes the same observation I do about people parking and driving in bike lanes 7 or more feet wide.

Wider is not better.

Got a few more bike lane widths to measure today. First, Emeryville's Horton, from curb to post: 5'7". These seem to work for keeping drivers out.

Just to the south, without posts: continuous bike lane blocking. #ZeroVision 23524K2

Over to SF. Here's the new 5th St. bike lane, first block in front of the Old Mint: 4'7" wide. So sad for Young's Market that they have to block a car lane now.

The next block, in front of the Chronicle building, is wider: 7'1". That is a bit over my theorized limit of 7 feet so I would not be surprised to see drivers sneaking in to park here.

5th's bike lane gets wider the further south it goes. At Bryant/Brannan it is 9'5", easily wide enough for parking. Note the floating yellow stripe indicating a commercial zone, and the lack of a red curb that might help deter bike lane blocking.

The brand new sidewalk-protected bike lane on Townsend is 9'10" wide, except at the utility pole choke points where it narrows to 6'2", 5'6", and a 5'1" / 4'1" split. Another cyclist tried to pass me right at the 5'6" narrows - don't fucking do that.

This last choke point is only 4'11". I'd use the face-palm emoji but we're not supposed to touch our face.

16th at the new basketball arena: 8'11" eastbound, 7'4" westbound. Both get blocked daily by people loading stuff. Here's a typical example - parked correctly, but still using the bike lane as a staging area.

New K71-protected bike lane in Oakland, San Pablo between W. Grand and 20th. Note the extra post narrowing the entrance, so drivers can't sneak in. The post-to-post width there is 6'10", under the magic 7' threshold.

Also note the driver blocking the lane just past the posts.

Oakland's Telegraph Av. parking-protected bike lane is finally getting posts! And they're big fat K-71s too. Unfortunately @OakDOT didn't add a post at the entrances, like the above San Pablo installation. Anyway: 8'2" wide, so drivers will park here, like the guy up ahead.

SF's Townsend got new protection between 8th and 7th. 7'4" at the entrance, 9'2" after that. Drivers still blocking the unprotected parts though.

7th got some new protection too. On this block it's 8'10", narrowing to 6'8" at the corner where there wasn't room to do it wrong.

New parking protected bike lane on Fell, next to the GGP panhandle! It's 6'9" from curb to post, just right.

However, I can't figure out the point of this mashing zone and pocket bike lane at Masonic. The traffic lights there already have a bikes-only phase, why not keep the bike lane on the left and use that?

Also this dip is gonna be a problem for the go-fast folks.

New protected two-way cycle track across the Lefty O'Doul bridge. Not gonna measure it because cycle tracks have to be wide, but the entrance posts should prevent driver abuse.

No posts narrowing the exit though. Want to bet someone backs in?

The next segment of protected bike lanes on Telegraph has gotten it's bollards. Still needs green paint. But I can measure the width: 7'3", slightly too wide. Maybe it'll be ok.

New protection on Embarcadero by Waterbar / Epic, where the valet parking has been a constant problem. Curb to post width is exactly 7', just right.