Generally, when I stumble across an unusual bit of infrastructure, I can figure out what’s gong on after some careful scrutiny. But bicycle and pedestrian markings have gotten so variegated and complicated that, more often than not, I’m left scratching my head. I pondered the rationale for a weird crosswalk in Baltimore a few months ago, but I didn’t quite hit the bull’s-eye. Here’s another example 50 miles away, in the nation’s capital, where I can only guess what they were trying to achieve:Along the bustling U Street NW corridor on the boundary between the Shaw and Logan Circle neighborhoods, we see this protected bike lane on the intersecting street.
Within the last decade, this means of protection has become much more commonplace: where bicycles receive the space between the curb and the on-street parking zone. It has proven safer for bicyclists than the more common place and conventional solution: the stripes that separate the parking zone from the cartway, a situation where bicycles must maneuver around both moving cars that veer into their lane as well as the swinging doors of people alighting from their parked vehicles. Dangerous. In the photo above, the Public Works Department in Washington DC has dedicated an approximately two-foot clearance area (indicated by the slash marks that are perpendicular to the curb) and reinforced it with white reflective stanchions that have a bit of the effect of bollards. No moving vehicles or swinging car doors to threaten cyclists. Additionally, the width of the bike lane and the protected zone are sufficient that both directions of bicycle travel can share the one side of the street, even though, in this case, the direction the parked cars are pointing indicates that the street is one-way for vehicles. Therefore, beyond just protection, the striping affords bicycles an added level of mobility and freedom over cars. Terrific; exactly what bicycle advocates want to see.
But then, just a few feet further—visible in the foreground, and approaching the intersection with U Street—the bike lanes do something unusual: they diverge.At this point, the two-directional bike lanes have a forbidden median that is as wide as the lanes themselves, combined. More bollards, and a lot of faded yellow painted slashes that essentially render at least 40 square feet of the roadway unused. Looking at the other side of the intersection, north of U Street, we witness a similar configuration.Though it’s not completely easy to discern, the two bike lanes diverge again, creating a sort of inverted Y-shape, with a triangular off-limits zone indicated through more yellow painted slashes.
Does this arrangement help manage the flow of bicycle traffic? My initial speculation, especially upon seeing the lanes diverge more dramatically on the side closer to me (the first two photos) was that the shape creates some added surface area for the bike lane approaching the intersection and stoplight, giving bicycles more room to assemble while waiting for a green, without accumulating too much and creating backups further down the lane. But that speculation doesn’t work for a variety of reasons: 1) the Y-shaped intersection on the north side of the U Street intersection does not apply to the bicyclists stopped at the light, so it’s inconsistent; 2) it’s a protected bike lane, so there’s no danger of conflict with vehicles; 3) it’s two-lane for the bicyclists as well, so a very slim chance of collisions if there’s significant congestion; 4) Washington DC never has enough bicyclists to experience congestion at intersections. No doubt the city is among the most bike-friendly in the US, but it’s hardly Copenhagen or Amsterdam. The volume of bicyclists remains thin enough that traffic is unthinkable. At the very least, I could see some utility in this shape if the lane approaching the intersection split into two turn lanes, giving bicyclists seeking to go right or straight one option and those going left the other. But that’s not what we see here, and the chances of such a need arising are slim; in a country where a small share of people bike regularly, bicycle traffic jams simply don’t take place.
The reason for the lanes to diverge remains a mystery. My only other guess is that it’s less about the lanes and more about the adjacent on-street parking.On less busy urban streets (local roads), on-street parallel parking can take place almost up to almost the corner without interfering with traffic flow. But on protected bike lanes along busier collector roads, the parked cars aren’t up against the curb—they’re floating in the middle of the street—and vehicular speeds tend to be faster. Thus, a car with its nose right up to the intersection and crosswalk could create real hazards, not just in the possibility that turning vehicles might clip the parked ones, but for the safety of bicyclists, who would be hard to spot if they were hiding behind a parked car right at the intersection. When the light turns green, the motorist could turn right into the bicyclists, if they were lurking in their lane behind a parked car. Thus, I’m increasingly suspecting this unusual configuration where the lanes diverge is more of an artificial manner of forcing the parked cars out of the last 10 yards or so before the intersection and pedestrian crosswalk.
Good bicycle design and engineering may not be in its infancy, but it’s still barely beyond crawling. The planners and engineers at Washington DC’s Public Works Department probably have a more sophisticated reason for this approach—one that might even afford some benefit to the bicyclists—but it’s not abundantly clear to an occasional rider like me. And it might not be clear to any but the most avid bicyclists, which does elicit cause for concern: are the continuously evolving stripes, sharrows, and stanchions fostering an increasingly dense, byzantine network of messages that might confuse all bicyclists? Fortunately, urban bicyclists, on average, still aren’t moving as quickly as cars, so they get a bit more time to process the signals and symbols. Unfortunately, a false move for a manually powered vehicle that weights about one-hundredth of the typical car can still yield far more devastating consequences. As urban bike lane design goes, we’re still in a trial-and-error phase. Maybe, in the years ahead, the demand will rise for a consistent series of bicycle lane rules and design standards. But it might take the American equivalent of Copenhagen to get us there.
15 thoughts on “Two lanes diverge on a road, and I took the time to blog about it.”
Courtney Reynolds… ideas?
Thanks for your interest, Katie–another blog follower PMed me and I think we have an answer: https://twitter.com/paytonchung/status/980486272539119616
So it turns out it really is about visibility, though it’s a shame to lose so much road real estate in the process…
My friend is an advocate for cycling in FL so I thought she might be interested in your piece. Also, I recently started cycling to school with my kids and became hyper-aware of how inadequate a typical bike lane feels when you’re the cyclist (if one even exists).
Agreed–painted stripes kind of have that “better than nothing” approach, don’t they? I’ll admit that many of the lanes in DC, which are protected by a buffer strip and bollards/stanchions, are actually pretty good. But I still think maneuvering in traffic on a bike with kids would just be unbelievably scary… Florida is now one of the most pro-active states in the country for bicycle and pedestrian planning…but only because it was consistently rated #1 in the nation for fatalities up until that point. Nice to hear from you!
We’re actually in Colorado and my town has some pretty great paths for biking. Even so, commuting by bike can be a challenge (and scary!), especially with kids.
I remember completing a survey shortly after the 15th St. bike lanes opened up, and one question was if I knew why the two lanes split at every intersection. I said I didn’t. But they asked the question as if I should have known.
Agreed–it’s not exactly obvious is it? I was only able to figure it out after I wrote a blog about it; I didn’t have a clue back when I took those photos. And while the Twitter link above suggests I eventually got it right, I would never expect most people to contemplate it the way I did. Clearly too much free time… Thanks as always for your thoughts.
It was definitely a head scratcher. I looked at all the intersections along the 15th street bike lane and they were all just a bit different. The parking explanation made sense but didn’t fit other intersections. The intersections where it splits definitely have heavier traffic.
Yeah, I can’t help but think that the irregularity and confusion would make it tough for bicyclists, at least the first time around. They probably get used to it (and it’s most likely a very popular commuter route), but when vehicles have to switch lanes regularly to go through in an urban area with lots of four-way intersections, it creates lots of last-minute shifting and raises the likelihood of an accident. Bicycling will never be as thick with traffic (at least not in this country) so it probably doesn’t matter as much, but it’s still interesting that there doesn’t yet appear to be a standardized solution.
I would not find it at all confusing as a bike rider. While the lanes do shift a little in places it’s subtle and riders are used to the conditions varying a bit in a chaotic urban environment. I’m fine with no “standardized” solution because if there were one, engineers would be very pedantic about implementing it. This is something cycling advocates have fought against for a long time: “can’t do it, doesn’t meet the standard”. That’s one really nice thing about the NACTO guide, it provides a lot of flexibility with looser guidelines that work better in constrained urban environments. The topic of whether US cities like Washington could significantly increase the bike transportation mode is not a fait accompli, it’s a matter of public policy and that certainly could change, but that might be a better beer conversation!
Good counter-argument. My concern was that, with a lack of standardization, bicyclists could get confused by the onslaught of inconsistent signals and stripings, reacting inappropriately and with dangerous consequences. But since bikes generally can’t go nearly as quickly as cars, the need for quick reflexes diminishes somewhat, and they can be more deliberative than a vehicle (unless of course they’re reacting to a driver’s rash decision). But you do have a point that standardization could result in a widespread dumbing-down of the overall biking environment, resulting in complacency among public works departments and diminished desire to improve. Maybe the truth is somewhere in the center, between clearly articulated guidelines and customizable solutions: the best features of NACTO applied for non-motorized, manually powered vehicles. We could be so lucky!
The obvious solution is not to paint lines on the street and put up pretty little pylons, but to change culture. Those of you who want your own safe space are a true bicyclist’s worst enemy. You’re virtually ensuring a future where we will not be allowed on the vast majority of roads, but instead relegated to some trash filled gutter every tenth block. Thanks for nothing…really.
It’s my experience that the “true believers” (extremists) are usually a movement’s worst enemies.
“Serious cyclists” are not going to change America’s car culture by themselves, and your natural allies are the “timid cyclists” who want cycling to be safer and easier for them. You are not going to make them “braver” or more like you. So perhaps resign yourself to being a loud and permanent minority who never achieve actual change…or work with those you disdain. Your choice.
Sorry for the thread hijack, Eric. 🙂
No worries–this seems like a perfect niche demonstration of the Tocqueville Effect. And I agree that the best way to shift the culture is with the center of the bell curve: those who like biking (no phobias) but are terrified outside of certain environments. That’s one of the reasons the Cultural Trail is so great–not because it brings out the bike messengers, but because it lures the soccer moms. We’ve made incredible progress in just the last ten years, and I don’t ever want to discount that progress even while I continue to point out oddities and shortcomings in bike design.
While walking, I have chased more than one leisure cyclist off the sidewalk where The Cultural Trail is wide enough to have separate paths. That kind of illustrates your point about confusion from non standard arrangements within a small area…even though the divided paths are clearly signed.
I agree with Alex, maybe non-standard does make everyone pay more attention. One good way to slow down a motorist is to introduce a little confusion through an unusual configuration.