Tag Archives: safety

Truck side skirts: reliable way to prevent cyclist fatalities?

No, not reliable. And they are also supposed to confer an aerodynamic advantage. Some do, some don’t.

Some have a smooth surface which can deflect a cyclist. That is still no guarantee that the cyclist will escape serious injury or death. Other side guards are only open frameworks which can catch and drag a bicycle. A lot of what I have seen is little more than window dressing.

The side guard in the image below from a post on the Treehugger blog has no aerodynamic advantage and could easily guide a cyclist into the rear wheel of the truck.

Photo of truck side with guard from Treehugger blog.

Photo of truck side with guard from Treehugger blog.

A cyclist can easily go under the side guard shown in the image below, from a Portland, Oregon blog post. A cyclist who is leaning against the side guard is guided into the sharp edge of the fender bracket and fender, and the front of the turning wheel, which can pull the cyclist down. There is another wheel behind the one in the photo.

Side guard on City of Portland, Oregon water transport truck

Side guard on City of Portland, Oregon water transport truck

The side guard on a Boston garbage truck in the photo below — my own screen shot from the 2013 Boston Bikes annual update presentation — is only an open framework which could easily catch and drag a bicycle.

Side skirt on City of Boston garbage truck

Side skirt on City of Boston garbage truck

A truck which is turning right off-tracks to the right. A cyclist can be pushed onto his/her right side, and goes under, feet to the left, head to the right. On the other hand, if an overtaking truck contacts the left handlebar end, or if the right handlebar end contacts a slower or stopped vehicle or other obstruction, the handlebar turns to the right and the cyclist slumps to the left, headfirst.

To be as effective as possible for either aerodynamics or injury prevention, side guards must cover the wheels. Though that is practical, none of the ones shown do.

But no practical side guard can go low enough to prevent a cyclist from going underneath. The side guard would drag  at raised railroad crossings, driveway aprons, speed tables etc. Even if the side guard did go low enough, it would sweep the fallen cyclist across the road surface, possibly to be crushed against a parked car or a curb.

Fatalities have occurred when cyclists went under buses, which have low side panels — but the wheels are uncovered. The Dana Laird fatality in Cambridge, Massachusetts is one example. Ms. Laird’s right handlebar end is reported to have struck the opening door of a parked vehicle, steering her front wheel to the right and toppling her to the left.

Dana Laird fatality, Cambridge, Massacchusetts, 2002

Dana Laird fatality, Cambridge, Massachusetts, 2002

The bicycling advocacy community, as shown in the blog posts I’ve cited, mostly offers praise and promotion of sub-optimal versions of side guards, a measure which, even if executed as well as possible, offers only a weak, last-resort solution to the problem of bus and truck underruns.

Most of the comments I see on the blogs I linked to consider it perfectly normal for motor traffic to turn right from the left side of cyclists, and to design infrastructure — bike lanes in particular — to formalize this conflict. The commenters also would like to give cyclists carte blanche to overtake close to the right side of large trucks, and place all the responsibility on truck drivers to avoid off-tracking over the cyclists.

Cyclists are vulnerable road users, but vulnerability is not the same as defenselessness. It is rarely heard from today’s crop of bicycling advocates, but a cyclist can prevent collisions with trucks and buses by not riding close to the side of them. There’s a wild contradiction in playing on the vulnerability, naiveté and defenselessness of novice cyclists to promote bicycle use with measures — particularly, bike lanes striped up to intersections — which lure cyclists into a deathtrap. Regardless of whoever may be held legally at fault in underrun collisions, cyclists have the ability to prevent them, and preventing them is the first order of business.

Want to learn how to defend yourself against going under a truck? Detailed advice on avoiding bicycle/truck conflicts may be found on the Commute Orlando Web site.

Additional comments about the political situation which promotes underrun collisions may also be found on that site.

Danish story, video and comments on the Albertslund-Copenhagen “bicycle superhighway”

A reader pointed me to a news story on the politiken.dk blog about the Copenhagen/Albertslund “bicycle superhighway” which is getting attention and publicity. The reader’s comments on my previous post read:

Yeah, its kind of joke, but to be fair they are not called superhighways in Danish but Super bicycle tracks, and even then most agree that they are not really that super. There is a video of the entire route here if you scroll down a bit:

http://politiken.dk/debat/skrivdebat/ECE1615543/er-koebenhavns-nye-cykelsti-virkeligsuper/

The two next ones which will open are another story though, as they mostly have their own right of way, and use viaducts or bridges to cross streets.

So, better things may be on their way, but…I ran the article through the Google translator, and it appears in the link below in (sort of) English. The page includes the sped-up video of the entire route.

http://translate.google.com/translate?sl=auto&tl=en&js=n&prev=_t&hl=en&ie=UTF-8&layout=2&eotf=1&u=http%3A%2F%2Fpolitiken.dk%2Fdebat%2Fskrivdebat%2FECE1615543%2Fer-koebenhavns-nye-cykelsti-virkelig-super%2F&act=url

Here’s the video — warning, Shell diesel fuel ad at start, and you can only stop the video when you click on it, see the ad again and click on it to open a bigger ad! This workaround was needed to make the video visible on this page.

The one unifying factor of this route is an orange line painted lengthwise to identify it. The first part of the route is relatively tame. Barriers, unprotected intersections and other hazards pile up near the end.

Some representative quotes (I’ve translated from Googlish to English, thanks to an online dictionary and my knowledge of the neighbor language, German.):

From the article:

“I did not expect that I just had to detour on ordinary roads in residential neighborhoods. I did not see much of the green wave that is supposed to be in town. I do not think you can call it a super bike path,” the [politiken dk test rider] concluded.

From comments on the article:

- The section of tunnel under Motorring 3 is dark and miserably lighted. There are many riding schools (which, incidentally, should be forced to close and move out into a rural area!). The tunnel is usually filled with horse s***, and because you can not see in these tunnels due to poor lighting, you can only hope that you do not ride through any of it.

*****

- In the westbound direction, at the pitch-dark tunnels, you have to negotiate two sets of barriers. The point of these, other than to impede traffic, I do not know. But when you have to use all your mental energy to get through these, they constitute more of a hazard than a safety precaution.

*****

I have commuted between Roskilde and the northwest part of Copenhagen 2-3 times a week on a recumbent trike with an electric assist motor for 6 months (http://ing.dk/blogs/pedalbilen). When I used the “super path” the trip was about 3 km and 15 minutes longer. Especially the part of the route in Albertslund is very indirect and inconvenient. There are detours, barriers and ramps in most places, and it will for example not be possible to ride in a velomobile, as far as I can judge. The new route is comfortable and free of exhaust, but as commuter route it gets a failing grade compared with Roskildevej [a parallel, 4-lane divided but not limited-access highway with one-way sidepaths].

*****

- I didn’t see anything which shows that cyclists have priority over the other traffic. Unfortunately, the only thing new that I see is approximately 100 meters of new asphalt in two places near Rødovre, so that it is easy going. There are simply no real improvements for cyclists in relation to other road users! You can still find barriers, sharp turns, bumps and traffic lights. Why is there no new cycle path, e.g. along the western forest road, so you do not have to drive through neighborhoods with pedestrians and children playing? Why are barriers not turned 90 degrees, so users of the route have right of way?

Even if there were brand new asphalt on the entire route it would never merit the title “super”. Only when a route enables more or less continuous travel at high average speed (which motorists know from motorways) does it, in my opinion, deserve the massive marketing it is currently getting.

*****

…Bus passengers cross the bikeway. It seems quite unreasonable that there are no islands at bus stops where passengers have to wait when they get on and off. Thus cyclists must stop, and so, so much for the “super bike path”.

A ride on Comm Ave., Boston, Massachusetts, USA

Comm Ave. Boston: Kenmore Square, Mass Ave. underpass from John Allen on Vimeo.

This is a 4-minute continuous video of a bicycle ride in Boston, eastbound on Commonwealth Avenue through Kenmore Square, to and through the underpass at Massachusetts Avenue. I recommend that you view it on Vimeo site, in full-screen high definition.

Gordon Renkes and I each had a camera, so you can see both a forward and rearward view. We rode safely, and mostly by not using the special bicycle facilities.

Some highlights:

  • The block pavers, bricks and the granite curbstones used as borders for crosswalks made for a very bumpy ride across Kenmore Square and the next intersection.
  • The bike lane for the first block after Kenmore Square was unusable, due to double-parked vehicles. In the next block, it was unsafe, due to the risk of opening car doors and walkouts. One trucker was accomodating enough to park entirely outside the bike lane, inviting bicyclists to run the gauntlet between the truck and parked cars Gridlock Sam-style. We didn’t take the invitation.
  • As we waited for a traffic light, a cyclist raced past us on the right, entering the narrow channel between a row of stopped motor vehicles and one of parked cars. If anyone had walked out, or a car door had opened, the cyclist would likely have had too little time to react, and he would have had no escape route. At least he (and the pedestrian he could have struck) would have been fortunate in that one of the waiting vehicles was an ambulance.
  • There is a bike box along the route, and revealed an issue that I hadn’t noticed before. If the traffic light is red, you’re supposed to filter forward in the bike lane on the right, then swerve across two lanes of traffic to the middle of the 4-lane wide bike box, to be in line with the bike lane which is to the left of 2 lanes — see Google satellite view — note that this is an angle shot from the west. If the light is green, you could merge either before or after the intersection, but there is an advantage in merging before the intersection, as the counterexample of the video shows. You also don’t know when the light is going to change — so in either case, you make a widely divergent choice — merge left, or head for the bike lane at the right — based on insufficient information, and if the light is red, you also could be swerving abruptly across two lanes of traffic just as the light turns green.
  • The buffered bike lane in the underpass makes for an easier ride through the underpass, but where it connects to a narrow left-side bike lane outside the underpass, there is little clearance for motor traffic in the next lane, which is the faster of two travel lanes. There also is a risk of left-hook collisions. I used to ride in the right lane, claiming the lane, and that was simpler and less stressful.

More general comments:

  • The block pavers, bricks and curbstones buried in the street are not bicycle-specific, but certainly not bicycle-friendly. I predict that they will be paved over within a few years as they deteriorate.
  • The attempt to engineer a “bicycle friendly” or “low-stress” solution on busy, crowded Commonwealth Avenue is like ornamenting a pig with lipstick, costume jewelry and a party dress. The bicycle-specific measures, except the bike lane in the underpass, fly in the face of the way traffic works, and the way it uses this street. Experienced, competent cyclists like Gordon and me know how to avoid the hazards, but they worsen our experience anyway — it is in Kenmore Square (during another ride) that I first heard the call “get in the bike lane” in Boston. Less knowledgeable bicyclists garner a false sense of security, following the painted lines, and expose themselves unnecessarily to risk.
  • Meanwhile, other, better solutions beckon. I have long advocated that Boston designate and improve alternative routes on lightly-traveled streets for through bicycle travel. That would be especially easy in Back Bay, with its grid layout. My candidate for an alternative to Commonwealth Avenue would be Newbury Street, the next one to the south, a shopping street which could make a very nice bicycle boulevard, and which, with a little bridge across the Muddy River, would also connect under the Bowker Overpass into the Fenway area. A worse solution also has been proposed: the City is considering a so-called “cycle track” — a bikeway behind a row of parked cars — on the next Street after Newbury Street, Boylston Street. More about these topics later…

“Shared space” — longer video and discussion

This post is a companion to my earlier one titled “No Rules.” The video here shows my entire ride on Commercial Street in Provincetown, Massachusetts, with a forward and rearward view, while the one in “No Rules” shows only highlights in a forward view. I discuss the “shared space” phenomenon at length in this post.

Commercial Street is one lane wide and officially one-way, but it is heavily used by pedestrians and bicyclists traveling in both directions, to the extent that motorists can only travel at a very low speed and often must stop. Bicyclists also must take special care, ride slowly and often stop. Some do and others do not. Pedestrians need to be alert to the hazards. Some are and others are not.

“Shared space” has become a buzzword among people who want to “return the street to the people,” meaning, in reality, make the street into a pedestrian plaza — a social space. Pedestrians, then, serve as obstacles to slow down faster modes. “Shared space” advocates regard this as a benefit, and point to a reduction in the rate of serious crashes. This reduction, however, results from the very low speeds at which travel is possible in such an environment. Even so, there are safety problems. Even cycling at a moderate speed is hazardous to pedestrians — and equally, to cyclists who collide with pedestrians. As the video shows, I had to ride slowly and cautiously to avoid colliding with several pedestrians who made sudden, unpredictable moves.

Another buzzword is “no rules”. Sure, pedestrians can bump into each other without usually causing injury. “Shared-space” advocates, however, often consider cyclists to be like pedestrians — a serious misconception. Cyclists traveling at their normal speed can socialize only with each other, and are antisocial, not social, in a pedestrian plaza. Safe sharing of “Shared space” requires cyclists to travel so slowly that there is little advantage over walking. Cyclists and motorists in “shared space” must pay strict attention to the basic speed rule, to go no faster than is safe under the conditions at the time and place. Violate this, knock a pedestrian down, and then hope that you have good insurance. Other rules apply, as well, in many “shared space” installations: yielding before entering the roadway; overtaking on the left; exclusions or limited hours for motor traffic.

The one rule that most cyclists disregard on Commercial Street is established by one-way signs. Cyclists disregard it for a particular reason: there is no comparable street which allows travel in the opposite direction. Bradford Street, one block farther from the harbor, is hilly and carries regular motor traffic. Commercial Street is the location of businesses which appeal to tourists who pile off the ferries from Boston, while Bradford Street has few such businesses.

What would improve the situation here? The first thing I would suggest is to block off the west (up-Cape) end of Commercial street where it separates from Bradford Street so motor vehicles can’t enter, and to install signs directing them to use Bradford Street. I think that many of the motorists who enter Commercial street are tourists who don’t know what they are getting into. If they used Bradford Street instead, they would get where they are going sooner, and would need to travel at most one or two blocks on Commercial street to reach any destination. It might also be helpful to sanction contraflow bicycle travel, and paint a dashed line down the middle of Commercial street to encourage keeping to the right. Moving parking off Commercial street also could help, especially in the few blocks near the center of Provincetown where traffic is heaviest. That could at the very least allow more room for pedestrians without their getting into conflict with cyclists and motorists. There is an abandoned rail line — partly on a lightly-used dead-end street, and paralleling much of Bradford Street and Commercial Street. It could carry the bicycle traffic heading in and out of town.

Beyond that, I don’t see much that can be done. Commercial Street is what it is, a quaint, narrow street like those in many European cities. Short of a horrible disaster — a huge storm or tsunami which would destroy the entire waterfront — Commercial Street isn’t going to get any wider.

No rules?

Quite by chance, I encountered an advocate of “shared space” and had a conversation with him at the start of a ride I undertook to illustrate the concept. The advocate expressed that there are “no rules” in this kind of space, which is dominated by pedestrians. Do you agree?

The Six-Way in Rush Hour

Here’s another video showing conditions at the six-way intersection of 16th Street, U Street and New Hampshire Avenue NW in Washington, DC, where special bicycle facilities have been installed.

Also please see my earlier post about this intersection, with another embedded video.

Examples of Sidepaths in National Parks

A commenter on the Washcycle blog where I first read of the mandatory sidepath provision in the Transportation Bill had the following to say:

In most parts of the country NPS, BLM and other stewards of Federal land are the furthest things imaginable from builders of bike paths

It only takes a little research to prove that statement incorrect.

Consider the Cape Cod National Seashore.

I happen to have posted an article with photos of the Province Lands paths (near the tip of the Cape), so you can see what kind of path we’re talking about here.

The Nauset path near the south end of the park also parallels a road. These paths in the National Seashore were built long ago to a very low design standard. Roads paralleling these paths now have Share the Road signs, reflecting the reality that many bicyclists prefer to ride on them. The roads also are more direct, and serve some trip generators which the paths do not. With the proposed law, the NPS would have to take these signs down and replace them with bicycle prohibition signs, and the park rangers would have to busy themselves with chasing bicyclists off these roads, reflecting a prohibition which is inconsistent with traffic law elsewhere in Massachusetts.

More examples:

Yosemite National Park

Valley Forge National Historical Park

Chincoteague National Wildlife Refuge

Grand Teton National Park:

And quite a number more, I’m sure. Just search under the activity “Biking” on the page

http://www.nps.gov/findapark/index.htm

Transportation Bill Includes Draconian Mandatory Sidepath Provision

Concerning the transportation bill currently making its way through the U. S. Senate committee process, please see this analysis on the Washcycle blog.

The bill has adverse effects on funding, and also it contains the most draconian mandatory sidepath provision I’ve ever seen. Get-bikes-off-the road provisions like this one were deleted from the laws of most states which had them in the 1970s. This is on Page 226 of the bill:

(d) BICYCLE SAFETY.­The Secretary of the appropriate Federal land management agency shall prohibit the use of bicycles on each federally owned road that has a speed limit of 30 miles per hour or greater and an adjacent paved path for use by bicycles within 100 yards of the road.

The Washcycle comments on this:

Even if the trail is in very bad shape, and the road is perfectly safe, the Secretary will have no leeway to allow cyclists to continue to use the road if a trail is available. This is very bad policy. Among other things it would end biking on portions of the Rock Creek Parkway where the speed limit is 35 mph.

Note that this applies not only to roads in parks but to any Federally-owned road. If there’s a trail within 100 years of a road, then to get to a destination on the other side of the road this law would require you to lug your bicycle through some environmentally-sensitive area in a National Park, or through private property, or swim across a river. If the trail is covered with snow but the road is clear, you would still have to use the trail. The legislation does not even state that the trail has to serve the same destinations as the road, or refer to any standards for design, etc. Excuse me. The conclusion the states reached in the 1970s is based on a simple principle: let bicyclists decide. If the trail is better than the road, they will use it.

Furthermore, the Federal Government does not have jurisdiction over traffic laws. The states do. The predictable outcome is dozens of court battles which will be an embarrassment to the Congress. There also is liability exposure in restricting bicyclists to a substandard path.

I am sending a version of this message to my Senators, John Kerry (D-MA) and Scott Brown (R-MA). Both, by the way, are avid bicyclists.

All I see in the America Bikes document about the bill is about funding. I want confirmation that the lobbyists all of the America Bikes member organizations are working to have this provision deleted. I am a member of three of these organizations: the Association of Bicycle and Pedestrian Professionals, the League of American Bicyclists and the Adventure Cycling Association, and I need to know that they are supporting my interests. And, as a member of the National Committee for Uniform Traffic Control Devices (NCUTCD) task force currently working on revisions to the Uniform Vehicle Code, I am especially concerned about this provision.

A Cyclist Signs Up for Advanced Driver Training

What was an avid cyclist doing in a place like this?

I like to ride my bicycle but sometimes I have to drive.

Over 40 years ago on dirt roads and snow in Vermont, I learned to steer into a turn; to manage the situation when a car loses traction, rather than to blank out or panic.

I shot the video above recently, in a class with hands-on driver training which goes well beyond that. All of the instructors are racers. They test the limits of traction at every turn on the racecourse. But here, they are teaching skills for crash avoidance on the road.

My son took the class with me. He had taken a conventional driver training course and already had his driver’s license, but he had no experience handling a car at the limits of traction.

The InControl course begins with a classroom lecture. Our instructor, Jeremy, explained that driver training is broken in the USA: that over 40% of new drivers have a crash within the first two years; 93% of crashes result from driver error and so, are preventable. He also explained that he would be teaching about steering, braking, hazard perception and avoidance.

Jeremy handed a quiz sheet with 16 questions to check off, true or false. We were told to hold onto our quiz sheets because we would review them later.

The most compelling part of the course is the hands-on practice. It is conducted under safe conditions on a closed course, in a huge, empty parking lot, in cars with a low center of gravity; an instructor is always in the car. As shown in the video, we did the slalom — at first with an instructor driving; then each student took a turn driving. We learned how great the effect of small increases in speed can be on the ability to maneuver. We practiced emergency stops, then swerving while braking; we had the backing demonstration and the tailgating test, as shown in the video.

To learn how to anticipate potential hazards takes time, and experience. The InControl class can discuss this but not teach this. A driving simulator like the ones used to train airline pilots would help to build that experience under risk-free conditions. Video gaming technology is approaching the level that it could do this at a relatively low price. Computers are up to the task, but they would need multiple visual displays and a special “driver’s seat” controller. Lacking that technology, I have traveled many miles with my son, both as a driver and as a passenger, coaching him. His many more miles of experience stoking our tandem bicycle were a fine lead-in.

What did I learn in this class, with my nearly 50 years of experience as a licensed driver? Several things of importance — among them:

  • Despite my decades of experience, I answered several questions on the quiz incorrectly. I’m not going to provide a crib sheet– go take the course.
  • There is a very significant advantage to having different tires for summer and winter use, due not only to snow but also to temperature difference. Winter tires have “sipes” — small grooves –to develop a “snowball effect” — actually picking up snow so it will adhere to other snow, and improving traction. Tires should be replaced when tread is still twice the height of the wear bars.
  • Side-view mirrors should be adjusted wider than I had been accustomed to — so their field of view starts where the windshield mirror’s field of view ends.
  • The National Highway Transportation Safety Administration’s standards for a 5-star safety rating are lower for SUVs than for passenger cars, as a result of industry lobbying (Any surprise?)
  • Importantly, that antilock brakes do more than allow shorter stops. They allow steering during emergency braking, and we practiced this as shown in the video.
  • Most importantly, to me as a cycling instructor, that learning to manage risks is essentially the same for bicycling as for driving a car. The attitude is the same, and hazard recognition and avoidance are similar. One important difference is that a well-trained cyclist’s brain is the antilock braking controller on a bicycle.

As I write this today, my son has driven himself to his classes at the local community college 12 miles away. Like any parent, I cross my fingers every time he goes out the driveway, but I am pleased to report that he has is cautious and calm as a driver and that his driving inspires confidence, with exceptions at a very few times.

I wish he didn’t have to drive. I don’t like the environmental burden it imposes, and I don’t like the risk. If public transportation were at all reasonable, he would be using it. If the college were half as far away, he’d be riding his bicycle at least on days with good weather. For now, his getting a college education wins out over those concerns…

Scaling up and scaling down

New York bicycling advocate Steve Faust has stated that some ways of accommodating bicycling do not “scale up” — that is, they work with small numbers of cyclists, but less well with larger numbers.

His central complaint is that use of roadways with no special bicycle facilities, according to the conventional rules of the road, does not scale up well.

I might put that a bit differently. After all, more cyclists need more room. Mass rides such as New York’s own 5-Borough Tour avoid special bicycle facilities and occupy the entire width of Manhattan’s multi-lane avenues. Motor vehicles are excluded while these rides pass through. Interaction within the group of many thousands of cyclists is for the most part according to the conventional rules of the road, and falls short only in that many of the participants are inexperienced.

On roadways carrying both cyclists and motorists, cyclists inconvenience motorists when the motor traffic could go faster — that is, when there are many cyclists and few enough motorists that they could travel unimpeded, if not for the cyclists. Motorists inconvenience cyclists when motor traffic is congested, and stopped or traveling slower than cyclists might want to go. Level of service always declines as a road becomes more congested, and it declines faster when vehicles have differing speed capabilities.

On the other hand, there also are situations in which operation as intended does not scale down to smaller numbers.

Motorists are more likely, for example, to yield to a crowd of pedestrians than to a single pedestrian.

Another example is the leading pedestrian interval: the walk signal goes on a couple of seconds before motorists get the green light. The leading pedestrian interval is intended to get pedestrians moving out into the intersection before motor traffic can begin to turn across a crosswalk, encouraging motorists to yield to the pedestrians. The same approach is used sometimes on bicycle facilities, for example on the Boulevard de Maisonneuve bicycle sidepath in Montréal, Québec, Canada. But a leading interval only works if there is someone waiting to cross when the signal changes. With smaller numbers, so the first pedestrian or bicyclist reaches the crossing after the motorists get their green light, the leading interval’s only achievement is slightly to reduce the capacity of the intersection.

The same issue can occur with any “conflict zone” with poor visibility as users approach, including the “bike box” or bicycle waiting area ahead of the stop line for motorists at an intersection. Once one cyclist is in a “bike box”, a motorist is unlikely to move forward, because that would require running over the cyclist. Therefore, the bike box is then safe for the entry of other cyclists, at least into the same lane in which the first cyclist is waiting.

The”bike box” works as intended when there are large numbers of cyclists so the first one arrives well before the traffic signal turns green.

If there are few cyclists, so the first one is likely to arrive just as the traffic signal turns green, then there is the potential for a right-hook collision, or a motorist’s colliding with a cyclist swerving into the bike box.

Safety requires that there be enough cyclists that early-arriving ones block the way of motorists, or at least alert the motorists that others may arrive. This safety factor does not scale down to small numbers.

Research in Portland, Oregon shows that only 5% of bicyclists swerve into the bike box when they are first to arrive; about 35% if they arrive later. The reluctance of the first-arriving cyclist reflects risk avoidance to some extent, due to not knowing when the traffic signal will change, but also that the swerve lengthens the cyclist’s trip — none of the Portland bike boxes are designated for left turns. The later-arriving cyclists are to some degree protected by the arrival of the first one, but also they either have to wait behind or move over to the left of that cyclist, into the bike box.

“Safety in numbers” claims become rather interesting when such issues are considered.

The design challenge is to achieve efficiency and safety of all travelers, regardless of whether numbers are large or small.