Tag Archives: Bicycling

Montreal sidepath protects?

A classic right-hook collision occurred on August 26, 2015 in Montreal, where the cyclist was riding on a sidepath.

Here’s a news report on the crash.

As I’ve said repeatedly, sidepaths do not prevent crossing and turning collisions.

The sidepath in this crash is in a block folliwng a steep downhill. The cyclist might have been be overtaking the truck which turned right across his path.

I have cycled through the crash location and shot a video of my ride. It is here.

Rue Berri from Cherrier to de Maisonneuve, Montreal from John Allen on Vimeo.

Michael Colville’s Pitch

About the video here by Mikael Colville of copenhagenize.com:

Mikael Colville’s talk in the video is introduced by a video clip of a rather sorry infrastructure situation, with a crowd of bicyclists slowly making their way forward, cramped in a narrow passage to the right of an opaque barrier, while a line of cars turning right must yield to the cyclists after turning past the barrier. To me, this choice of a clip conveys the message “look, we are morally superior, motorist, we’re going to make it hard for you: you have to yield to us.” It doesn’t say anything about making bicycling more convenient, or anything but a nuisance to people who might think of switching from motoring. Or that whoever chose this location had any other sense about infrastructure — certainly none about sight line hazards.

And the music — the Rolling Stones’ Sympathy for the Devil! Now there’s an odd choice!

Similarly, at the end, there is an overhead drone shot of a bridge which has recently been restriped from four to two lanes of motor traffic, to add street level bike lanes next to already existing bikeways behind curbs. The implication is that bicyclists are winning by taking space away from motorists, and that space is to struggle over, not to share. In this case, on a bridge, I’d agree that bike lanes are suitable, but are four needed? What happens where they turn off at the end of the bridge while motor vehicles can go straight? We don’t see. Who knows?

The talk is all about marketing. The core of his message is that guilt-tripping people about environmentalism doesn’t work, and we must use marketing to make bicycling look attractive. Two products which Colville discusses for purposes of comparison, sewing machines and vacuum cleaners, are both highly useful labor-saving devices which quickly became popular for that reason, but he doesn’t mention that. He does praise improvements which made them more compact and useful in the home, but mostly, he praises the decorations on sewing machines which made them more attractive to homemakers.

My mother owned a Singer treadle sewing machine, and indeed it was a beautiful product — to some degree because of the flower stencils but also because of its elegant product design, with a table to hold supplies and attachments, and into which the machine could be folded down to make the table useful when the machine wasn’t in use. Treadle power was perfect for the pre-electrical era, and the wheel on the right end of the machine could start, slow or stop it with precision. Not to speak of my mother’s machine’s being several decades old and still working perfectly.

My mother also owned a 1950-ish Kenmore (Sears brand, made by Electrolux) vacuum cleaner, and it was an esthetic horror, shaped like an airplane fuselage, painted dull gray and very loud. She made much more use of the vacuum cleaner than of the sewing machine.

Colville says that we must market bicycling like these products. He deprecates “the 1%” of people who will wear fancy cycling clothing” — guilt by association with political class struggle, divisive, and also a reference to the categorization which Roger Geller made up, pulling the numbers out of his head, only to be followed up by a home-town study which found that his numbers were exactly right (surprise!).

Colville says that people are conservative and don’t want to stand out. But, tattoos peek out from under his plain white T shirt.

I don’t think that bicycling can be sold by marketing alone. It must be practical and useful like a sewing machine or vacuum cleaner, or people won’t use it for daily transportation. Though some people like to show off with Spandex and carbon fiber bikes, others wear street clothes and ride beater bikes. Some do both. Should instructors even care? We make bicycling more practical for any cyclists by helping them to do it well — and offering informed opinions on what works, or not, in bicycle planning and infrastructure.

The Slow Ride, redux

Bob Sutterfield writes:

I don’t ride fast so I can participate safely in traffic.
I participate in traffic so I can safely ride fast enough for my needs.

If I were to ride in the gutter, on the bike path, in the door zone, on sidewalks and cycle tracks, etc. I could reduce my risk (probably to an acceptable level) by traveling slowly – at near-pedestrian speeds. That slower speed would give me more time to react to the hazards present in those environments.

But I use my bike for purposeful travel. I don’t have time in my day to travel as far as I need to go, if I were constrained to moving only at near-pedestrian speeds. In order to get where I’m going in a practical amount of time, I need to be able to ride at the speeds I’m capable of sustaining on a bicycle. And I need to do it more safely than if I were in the gutter or on a bike path or in the door zone – I need the safety and convenience of the travel lane. That speed is what the travel lane is designed to accommodate, and that’s what the ordinary traffic laws are designed to enable.

If my choice of travel by bicycle is restricted to hazardous areas like gutters and bike paths and cycle tracks, I’ll choose another way to travel – something motorized so I don’t suffer those restrictions.

Lane Control on Lexington Street

Here’s a video showing a bicycle ride on a constant mile-long upslope, at speeds of 10 to 12 miles per hour (16 to 20 km/h), on a suburban 4-lane speedway with narrow lanes and no shoulders, the most challenging street in the community where I live. Motor taffic was very light, and auite fast. Points made:

  • Lane control is not about riding fast: it is about controlling one’s space.
  • Lane control is necessary so motorists will overtake at a safe lateral distance on a street with a narrow right-hand lane.
  • By requiring motorists to make full lane change, lane control lets a cyclist with a rear-view mirror confirm well in advance that motorists will overtake with a safe lateral distance.
  • With the light traffic on a multi-lane street, a slow bicyclist does not cause any significant delay to motorists.
  • Most motorists are cooperative.
  • A few motorists are abusive — even though they can easily overtake in the next lane —  but they too overtake safely.
  • American traffic law supports lane control.

Lane Control on Lexington Street from John Allen on Vimeo.

Bruce Epperson’s observations on transportation funding

Bicycle historian Bruce Epperson has written a paper examining trends in transportation funding in the USA from the 1960s to the present. It makes interesting reading. With his permission, I have made the paper available in PDF format on this Web site:

http://john-s-allen.com/pdfs/epperson-funding.pdf

M. Kary on the epidemiological approach to traffic-safety research

M. Kary has released the manuscript of his paper on the unsuitability of the epidemiological approach in studying traffic safety.

Unsuitability of the Epidemiological Approach to Bicycle Transportation Injuries and Traffic Engineering Problems
Author: M Kary
Injury Prevention 2015;21:73-76, Published Online First 14 August 2014

First paragraph of the abstract:

Bicyclists and transportation professionals would do better to decline advice drawn from characteristically epidemiological studies. The faults of epidemiology are both accidental (unpreparedness for the task) and essential (unsuitability of the methods). Characteristically epidemiological methods are known to be error-prone, and when applied to bicycle transportation suffer from diversion bias, inappropriately broad-brush categorisations, a focus on undifferentiated risk rather than on danger, a bias towards unsafe behaviour, and an overly narrow perspective. To the extent that there is a role for characteristically epidemiological methods, it should be the same as anywhere
else: as a preliminary or adjunct to the scientific method, for which there is no
substitute.

You may read the entire manuscript here:

Kary2014UnsuitabilityOfEpid.pdf

A review of the film Bikes vs. Cars

I knew I’d have a problem with the film just based on the the title.

There can be animosity between people on bikes and in cars, but bikes and cars are machines, which have no feelings and generally don’t get into trouble unless there is a person is behind the steering wheel or the handlebars. The title “Bikes vs. Cars” reminds me of a frequent complaint of bicyclists who have had incidents in traffic, “the car didn’t see me.”   The title and that statement both reflect a fear-based mental block which has led to the inability to conceive of the car as a machine under control of a human, with whom it is possible to interact, and so, much more often, to avoid incidents…

Enough. There’s more to say. My facebook friend Kelley Howell has posted a detailed review, which follows here:

***************

Why I think the film, Bikes Vs. Cars, is a waste of money:

by Kelley Howell

It was a scattered, gawky film filled with untenable contradictions. Some thoughts:

The film switched back and forth between a desire to own the streets and use them as if they belonged to bicyclists who have a right to drive on them, free of cars, but then it dropped its pretense to militancy asking for small slivers of space on the edge, as if if that edge were some Magic Kingdom of safety. On one hand, the people in the film seem to be demanding a right to take the entire road and get the hated cars off it. On the other hand, it’s all about scampering out of the way, deferring to a dominant majority no one knows how to handle, let alone challenge.

As an example, there was a line in the film which went something like this: “At 1 AM, during the quiet of Carmeggedon in LA. I sneaked on to the 405 and rode my bike on this massive highway. It was beautiful. I owned that feat of human engineering. For the first time, I felt it was a marvel of human engineering that was made for me.”

Then they switch to Sao Paulo in Brazil, to capture the happy reactions of bicyclists who learned that the city is laying down 100s of kilometers of too narrow bike lanes in a very congested city where few people appear to follow traffic law to begin with. I was hard pressed to imagine all these scrappy motorists would respect the painted lines of a 4 foot wide gutter bike lane.

Which is it: do you want to drive a bike on that feat of human engineering, the 405, or a 4 foot bike lane with cars passing too close, driving out into your path, and right- and left-hooking you constantly? How is that demanding your rights? How is it safe? Accepting a scrap of asphalt, some of it carved out of a gutter built for sewer water? After all that rhetoric of wanting access to feats of human engineering, how is that you want to operate in a gutter bike lane?

The film trades in the imagery of the bicyclist, rolling free, free of motorists, free of the burden of a body on pavement, free because it can dodge the confines of hated “traffic”. The magic of the bicycle is its thrift, its speed, and its nimble ability to slip through crevices of urban congestion. It is at once traffic and the supposed escape from it.

But this is reminiscent of the propaganda that dominates the most pedestrian – har! – of auto advertisements where cars mean freedom, an open road, an endless horizon. This imagery in commercials is a stark counterpoint to the reality of miles of congested freeway, gridlock, and, well, to borrow a phrase, the hell that is other motorists at rush hour.

This trope — the bicycle as freedom, magically evading being captured in traffic — is present in an amusing fantasy entertained in the film: pulling 20% of all motorists off the Los Angeles roads and reinserting them with their derrieres planted in bike saddles. Apparently they will accomplish their 14.7 mile commute on their Dutchie or Cruiser, pedaling along at 10 mph?

Going by LA county numbers, 20% of the ~4.5 million motoring commuters is 900,000 bicyclists. Even if their commute where far shorter – say a manageable 5 miles at 10 mph — that’s a lot of bicyclists who get to share those four foot wide gutter bike lanes. Good luck with that!

Then, there was a main protagonist, name escapes, in Brazil. She says, to paraphrase, “What I want is some respect for human cooperation.” And then the film plugs away about the lack of bike lanes. Having apparently conceded that motorists will NOT actually give bicyclists that respect or cooperatively share the roads, they ask for a sliver of space in the gutter.

Which is fine. Really. If that’s what you want. But don’t imagine segregating modes is about cooperating. It’s rather about demanding public resources be spent on gutter-based infrastructure in Brazil precisely because motorists WILL NOT share the road. No one has actually changed the domination of motorists. In this “victory,” existing configurations of power remain the same, leaving bicyclists just as powerless as they always were, only now they are marginalia set off by 6 inch stripes of paint.

The incident with the Dutch cab driver was high camp and deserves its own post. It was my impression that the cabbie staged the whole thing, a real drama queen pining for his 5 minutes on camera. Basically, it was exemplary of what Nietzsche called a transvaluation of values[1]: an opportunity for bicyclists everywhere to make the motorist suffer for a change[2].

The problem is that this is an exercise in punishing schadenfreude. We are all supposed to love it that the roles have reversed in the Netherlands. The taxi driver has to be troubled, delayed, and dominated by the majority, bicyclists. We get to engage in gleeful enjoyment to see him upset, angry, cowed by the throngs of bicyclists blocking his every move. There! Take That, you bad, bad motorists. How do you think it FEELS to be marginalized like we were?

This is a stupid and shameful sentiment that shouldn’t be tolerated by anyone doing bicycling advocacy. But it is, unfortunately, celebrated by too many participation advocates – including this film, which trades in cheap theatrics and, well, quite frankly, trashy propaganda. At least have the decency to be sophisticated about it if you are going to trade in such infantilizing sentiments.

[1] I am unhappy with the choice of ‘transvaluation of values’ to express what I mean here. But it’s been a longass day. Tant pis!

[2] As for the transvaluation of values thing, for more detail on the problems with this position, see Wendy Brown’s work States of Injury: Power and Freedom in Late Modernity. Here, Brown captures the problem as one where, basically, an oppressed or marginalized group rises in power and status, promoting a compulsion to repetition rather than liberation:

“Initial figurations of freedom are inevitably reactionary in the sense of emerging in reaction to perceived injuries or constraints of a regime from within its own terms. Ideals of freedom ordinarily emerge to vanquish their imagined immediate enemies, but in this move they frequently recycle and reinstate rather than transform the terms of domination that generated them. Consider exploited workers who dream of a world in which work has been abolished, blacks who imagine a world without whites, feminists who conjure a world either without men or without sex, or teenagers who fantasize a world without parents. Such images of freedom perform mirror reversals of without transforming the organization of the activity through which the suffering is produced and without addressing the subject constitution that domination effects, that is, the constitution of the social categories, “workers,” “blacks,” “women,” or “teenagers.”

It would thus appear that it is freedom’s relationship to identity-its promise to address a social injury or marking that is itself constitutive of an identity that yields the paradox in which the first imaginings of freedom are always constrained by and potentially even require the very structure of oppression that freedom emerges to oppose.”

Another crosswalk confusion, and a fatality

In response to my post about confused yielding requirements where shared-use paths cross streets, Ryan Reasons has published comments on a recent fatal truck-bicycle crash in the Seattle, Washington area.

The photo below is from the KOMO TV/radio station news photo gallery.

view of crash scene

View of crash scene

My response to Ryan’s comments went into enough detail that I have decided to make a post of it. My response follows his comments below.

Ryan’s comments

@John S. Allen
The sort of confusion you describe may have cost Gordon Gray his life last Wednesday after he collided with a cement truck. The sheriff’s department says that Gray, a 70-year-old bicyclist from Washington state, was cycling on a MUP when he ran a stop sign, entered a street running parallel to the MUP and was struck.

King County Sheriff’s Sgt. Stan Seo says the Kenmore man was biking southbound on 65th Avenue Northeast Wednesday morning when he was hit by a cement truck heading west on Northeast 175th Street. Seo said Friday that according to investigators, it appears the cyclist did not stop at a stop sign and was hit in the intersection. He says the cyclist had turned off the Burke-Gilman Trail shortly before the accident.
The Associated Press, Komonews.com

If one accepts Sgt. Seo’s account of the events leading to the collision, then Gray was cycling on the MUP when he turned onto 65th Avenue to enter Northeast 175th street. (See this Google street map.) [You may  click on the link to open the view in Google maps, or click on the image below  to enlarge it — John Allen]

Location of Gordon Cray crash

Location of Gordon Gray crash

Note that the Google map shows three stop signs of possible relevance. The stop sign on 65th Avenue is located just north of the MUP and crosswalk. The other two stop signs are located on the MUP at opposite ends of the crosswalk.

Once Gray entered 65th Avenue from the MUP and headed south, did Gray have a legal obligation to stop at the stop sign on 65th Avenue? I don’t think so, because after turning south onto 65th Avenue the stop sign was behind Gray and facing north.

Let’s assume Gray committed a traffic violation (running a stop sign) when he turned from the MUP onto 65th Avenue. Does that mean Gray is legally at fault for a collision which occurred on his subsequent turn from 65th Avenue onto Northeast 175th Street?

The account given by local law enforcement suggests Gordon Gray will be blamed for his own death, even if Gray is not fully at fault. That seems like an injustice for Gray, an undeserved vindication for confusing cycling infrastructure, and fuel for more of the ugly jeers that accompany the deaths of cyclists who truly are at fault.

My response:

This is an interesting situation, and especially so as cyclists’ exiting from bikeways into parallel streets becomes more common with the increasing number of sidepaths (or “cycle tracks”, or so-called “protected bike lanes”). The path in question runs parallel to and just north of an east-west street (Northeast 175th Street) and crosses another street (65th Avenue) which Ts into it from the north, with a marked crosswalk. There are stop signs for the path at either end of the crosswalk, and there is a stop sign on 65th Avenue Northeast before the crosswalk, as is usual. So, once Gordon Gray was in the crosswalk, there was no stop sign directing him to stop at Northeast 175th Street.

This is not the same situation I described in the earlier blog post. What I described is the confusion from having stop signs at the ends of a crosswalk. Traffic in the street is supposed to yield to pedestrians in the crosswalk but confusion arises because the stop signs indicate that cyclists in the crosswalk must yield to traffic in the street it crosses. These two requirements contradict one another. The confusion manifests itself in drivers on the street stopping and yielding to cyclists, whom the stop signs direct to stop and yield to the drivers in the street. It is unclear who may proceed. In practice, the cyclists usually proceed, and often without coming to a complete stop, but also cyclists are faster than pedestrians, and a motorist’s stopping often requires a cyclist to stop when they would otherwise not have to, because the motor vehicle would have passed before the cyclist reached the crosswalk. There are also the issues which occur at other crosswalks, that the first motorist in one lane may stop, but a motorist in another lane may not, requiring extra caution of cyclists due to their higher speed and longer stopping distance than those of pedestrians.

What you describe appears to be that cyclist Gordon Gray entered the crosswalk, and then entered the parallel street. Indeed, there was no stop sign facing him once he had entered the crosswalk, as he did not pass the stop sign for traffic on 65th Avenue Northeast. The legalities here are somewhat confusing. Probably the stop sign before the crosswalk did not apply to entry onto the parallel street. Was Gray required nonetheless to yield before entering the parallel street? He would have been, if he had passed the stop sign on 65th Avenue Northeast. A T intersection without a stop sign is an uncontrolled intersection, and so he would still be required to prepare to yield, perhaps also to yield: in some states, at least Massachusetts, where I live, stop signs are not posted where one street Ts into another, but yielding is required. A concern for self-preservation would also require being prepared to yield, whatever the legalities.

There are a few things which the news report does not indicate:

  • Which way was Gray going? Was he originally westbound on the path? Then he would have had to look behind himself for the truck.
  • Was he attempting to head eastbound on Northeast 175th Street (or westbound on the wrong side), and so he was attempting to cross in front of the truck?
  • Just what was the truck driver doing, or about to do? There is a large concrete plant with two driveways, across Northeast 175th street from 65th Avenue. Concrete mixer trucks in the same colors as those in the news photo are visible parked there in the Google Maps overhead view. It is possible, for example, that the truck driver was signaling a turn, suggesting to Gray that he would turn left into the driveway east of 65th Street Avenue Northeast, but instead was continuing into the next driveway when his truck struck Gray. The location of the truck in the photo at the top of this post suggests that.

Some thoughts about self-driving cars

Google’s report on its self-driving cars:

http://static.googleusercontent.com/media/www.google.com/en/us/selfdrivingcar/files/reports/report-0515.pdf

Most than half of the collisions reported in this document are slow-speed rear-enders of the Google cars. That’s unusual. It might be that the behavior of the Google cars is more cautious than what human drivers expect, so the Google cars stop more often abruptly or at unusual places, and so are not tailgater-friendly. I’d suggest that the Google cars might be equipped with a rear-facing warning device.

It seems to me that self-driving cars will be able to avoid any collision where a human driver could avoid fault, and others. In other words, operators of non-automated vehicles (including bicycles) and pedestrians who follow the conventional rules of the road will be able to operate safely around automated vehicles. Vehicles with automated crash avoidance (not necessarily completely automated vehicles, even) will not rear-end bicycles, and so the premise of fear from the rear evaporates if automated crash avoidance becomes universal with motor vehicles. Self-driving cars will not be able to avoid collisions where avoidance would require violating the laws of physics. Vehicles with automated crash avoidance will be able to avoid some collisions in which the potential colliding vehicle or pedestrian is outside the field of view of a human driver, such as right-hook collisions, as long as there is a clear sight line to the automated vehicle’s sensor. Same for a large truck’s high hood which prevents the driver from seeing a pedestrian crossing in front.

Automated vehicles will not be able to avoid left-cross collisions where the bicyclist or motorist is passing on the right of other vehicles and concealed by them, or pedestrian dart-out collisions. The concept of fully networked vehicles is supposed to address this problem. All vehicles approaching the same place in the road network are envisioned as communicating with each other even when they are hidden from each other’s view. As someone with an electrical engineering degree, I consider this at best a very difficult proposition, and it might be described as a pipe dream. Bandwidth, interference and reliability issues lead me to ask “what could possibly go wrong?” Also, instrumenting every object on the road is only practical on a limited-access highway — no, not even there, because there will still be breakdowns, wild animals, debris. On other roads, is every pedestrian going to carry a transponder? I don’t think so.

Automated crash avoidance is easily hacked by rolling a trash can out into the roadway, and the like. The caution which automated crash avoidance inherently incorporates changes the dynamic from the one among humans, which can involve a game of bluff. To me, this means that automated vehicles will be extra-cautious in the presence of other drivers and pedestrians who do play the game of bluff, and so the progress of automated vehicles will be slow and erratic in, for example, Boston traffic.

All this leads to the question: does behavior change as these vehicles become more common? Does infrastructure change? Every new technology takes a while to find its feet. As Marshall McLuhan said, “We look at the present through a rear-view mirror. We march backwards into the future.” Do conditions become better or worse for bicyclists and pedestrians? And why? We have some control over this depending on the direction which is set for the technology, but also, time will tell.

Another serious issue I’ve heard mentioned is the car which is not only driverless but passengerless. There is potential for an increase in traffic if a car can be called to meet a person (like a passengerless taxi), or directed to drive around and around the block empty when a parking space can’t be found. I can’t say how serious this problem will be. To some extent, that depends on the extent of freedom afforded to people’s control over the driverless cars. It’s an interesting legal question involving private use of public space. We already face this question with congestion-pricing schemes. But on the other hand, fewer cars on the road might be needed, because the car-sharing model works better when a car can be called rather than only stationed. Again, time will tell.

Change lanes in a roundabout?

Ohio cyclist Patricia Kovacs posted an e-mail asking some questions about roundabouts:

Ohio engineers are telling us to use the inner lane for left turns and U turns. Both the FHWA [Federal Highway Administration] and videos available on our local MPO [metropolitan planning organization] website say this. I shared this when we asked for updates to Ohio Street Smarts. If the FHWA and MORPC [Mid-Ohio Regional Planning Commission] are wrong, then we need to fix it.

Would you review the 8 minute video on the MORPC website and let me know what I should do? If it’s wrong, I need to ask them to update it. This video was made in Washington and Ohio reused it.

Looking further into the problem, I see a related practical issue with two-lane roundabouts, that the distance between an entrance and the next exit may be inadequate for a lane change. The larger the roundabout, the longer the distance in which to change lanes, but also the higher the speed which vehicles can maintain and so, the longer distance required. I’m not sure how this all works out as a practical matter. Certainly, turning right from the left-hand lane when through traffic is permitted in the right-hand lane is incorrect under the UVC [Uniform Vehicle Code], and results in an obvious conflict and collision potential, but I can also envision a conflict where a driver entering the roundabout does not expect a driver approaching in the inside lane of the roundabout to be merging into the outside lane.

All in all, the safety record of roundabouts is reported as good (though not as good for bicyclists and pedestrians), but I’m wondering to what extent the issues have been subjected to analysis and research. When I look online, I see a lot of roundabout *promotion* as opposed to roundabout *study*. Perhaps we might take off our UVC hats, put on our NCUTCD [National Committee on Uniform Traffic-Control devices] hats, and propose research?

Thanks, Patricia.

This post was getting long, so I’ve placed detailed comments on the Ohio video, and embedded the video, in another post. I’m also working on an additional post giving more examples, and I’ll announce it here when it is ready.

Here are some stills from the video showing the conflict between through traffic in the outer lane and exiting traffic in the inner lane.

First, the path for through traffic:

Path for through traffic in a roundabout

Path for through traffic in a roundabout

Next, the path for left-turning traffic:

Path for left-turning traffic in a roundabout

Path for left-turning traffic in a roundabout

Now, let’s give that picture a half-turn so the left-turning traffic is entering from the top and exiting from the right:

traffic in a roundabout, image rotated 180 degrees

Path for left-turning traffic in a roundabout, image rotated 180 degrees

And combining the two images, here is what we get:

Conflict between through traffic and exiting left-turn traffic

Conflict between through traffic and exiting left-turn traffic

The image below is from the Manual on Uniform Traffic Control Devices, and shows similar but not identical lane use. The arrows in the entry roadways direct through traffic to use either lane.

FHWA diagram of a roundabout with lane-use arrows.

FHWA diagram of a roundabout with lane-use arrows.

Drivers are supposed to use their turn signals to indicate that they are to exit from the inner lane — but drivers often forget to use their signals. Safe practice for a driver entering a roundabout, then, is to wait until no traffic is approaching in either lane, even if only entering the outer lane.

A fundamental conceptual issue here is whether the roundabout is to be regarded as a single intersection, or as a series of T intersections wrapped into a circle. To my way of thinking, any circular intersection functions as a series of T intersections, though it functions as a single intersection in relation to the streets which connect to it. Changing lanes inside an intersection is generally prohibited under the traffic law, and so, if a roundabout is regarded as a single intersection, we get the conflicts I’ve described.

Sometimes, dashed lines are used to indicate paths in an intersection, when vehicles coming from a different direction may cross the dashed lines after yielding right of way or on a different signal phase. More commonly, a dashed line  indicates that a driver may change lanes starting from either side. The dashed lines in a two-lane roundabout look as though they serve the second of these purposes, though they in fact serve the first. These are shorter dashed lines than generally are used to indicate that lane changes are legal, but most drivers don’t understand the difference.

That leads to confusion. If you think of the roundabout as a single intersection, changing from the inside to the outside lane is illegal anywhere. If you think of the roundabout as a series of T intersections, changing lanes should occur between the entries and exits, not opposite them –though there is also the problem which Patricia mentioned, that a small two-lane roundabout may not have much length between an entry roadway and the next exit roadway to allow for a lane change. That is, however, much less of a problem for bicyclists than for operators of wider and longer vehicles. It would be hard to construct a two-lane roundabout small enough to prevent bicyclists from changing lanes.

My practice when cycling in conventional two-lane traffic circles — and there are many in the Boston, Massachusetts area where I live — is to

  • enter from the lane which best leads to my position on the circular roadway — either the right or left lane of a two-lane entry;
  • stay in the outer lane if leaving at the first exit;
  • control the inner lane if continuing past the first exit;
  • change back to the left tire track in the outer lane to prepare to exit.

That way, I avoid conflict with entering and exiting traffic in the outer lane, and I am making my lane change to the right in the slow traffic of the circular roadway rather than on the straightaway following it. This is what I have found to make my interactions with motorists work most smoothly. Why should a bicyclist’s conduct in a roundabout be different?

It is usual to be able to turn right into the rightmost lane of a multi-lane rodway while raffic is approaching in the next lane. I don’t know of any other examples in road design or traffic law in the USA where a motor vehicle is supposed to turn right across the lane where another motor vehicle is entering it. Bike lanes are sometimes brought up to intersections, though the laws of every state except Oregon require motorists to merge into the bike lane before turning. The illustration below, from Dan Gutierrez, depicts the problem.

Right hook conflicts, from Dan Gutierrez's Understanding Bicycle Transportation

Right hook conflicts, from Dan Gutierrez’s Understanding Bicycle Transportation video and course.

Applicable sections or the Uniform Vehicle Code are:

  • 11:304 (b) — passing on the right is permitted only when the movement can be made in safety.
  • 11:308 (c) — a vehicle shall be driven only to the right of a rotary traffic island.
  • 11:309 (a) — no changing lanes unless it can be done in safety
  • 11:309 (d) — official traffic control devices may prohibit lane changes
  • 11:601 (a) Right turns – Both the approach for a right turn and a right turn shall be made as close as practicable to the right-hand curb or edge of the roadway.