The Photoshop School of Traffic Engineering strikes again!

Posted on August 29, 2012 by jsallen

The Photoshop School of Traffic Engineering strikes again, this time in Minneapolis.

For background, please read the Minneapolis blog post: http://www.ouruptown.com/2012/08/potential-cycle-track-coming-to-36th-street

Also please read John Schubert’s comment on that post.

I’ve added a comment too — still in moderation as I write this, and I repeat the comment here, slightly edited and with this introduction.

The location described in the blog post, 36th Street at Dupont Avenue, is shown in the Google map below. If the full image doesn’t appear, clicking to refresh the page will probably fix that. The image is zoomable and draggable, but by clicking on “View Larger Map”, you may enlarge it, look down from different overhead angles, and switch in and out of Google Street View.


View Larger Map

36th Street is part of a grid system. Smaller, lightly-traveled 35th Street is one of several that could instead be configured as a bicycle boulevard (also called neighborhood greenway) like those in Berkeley, Eugene, Portland and Seattle, so bicyclists use the street as a through route while only slow, local motor traffic uses it. That is popular with residents and avoids the problems with sight lines which John Schubert has described.

Now for some comments on the pictures in the Minneapolis blog post. They are examples of of what I call the “Photoshop School of Traffic Engineering”, Or the “Anything Goes” school. Well, anything goes in a Photoshopped picture but not necessarily in reality.

Here’s the first picture from the blog post:

Photoshopped illustration of proposed "cycle track" on 36th Street in Minneapolis

Photoshopped illustration of proposed “cycle track” on 36th Street in Minneapolis

The caption for this photo in the blog post reads “[a] possible cycle track is being considered for 36th Street in Minneapolis.” As we’ll see though, the rendering in the picture is hardly possible.

In the picture, there’s already a sidewalk on both sides but now also a special lane so pedestrians can walk in the street. To make room for this and the bikeway, the blue car in the right-hand travel lane is squished to about 3 feet wide and that lane is about 8 feet wide. The text describes the bikeway as 10 feet wide, but it measures as about 12 feet wide based on the size of the bicycle wheels. 36th Street has a cross street every 300 feet, also entrances to back alleys and driveways in almost every block, but the picture shows maybe one intersection (note crosswalk lines) in the distant background. That is unreal. There’s some need for people to get in and out of all those cross streets, alleys and driveways.

Now, the other picture:

Another Photoshopped illustration of the proposed bikeway

Another Photoshopped illustration of the proposed bikeway

The caption in the blog post reads “[a] rendering of how a cycle track on 36th Street could look east of Dupont Avenue in Minneapolis.” Again, no, it couldn’t.

The bikeway is shown at a more realistic width. I’m not sure though how three travel lanes, a parking lane, 3-foot buffer and 10-foot-wide bikeway fit into a street which now has only two travel lanes and two parking lanes. Also note the car about to turn right across a lane of traffic and then across the bikeway at the one intersection shown. The lane with the closest car in it is shown as a lane of traffic, not a parking lane, or there would be signs and markings to indicate that. Assuming though that it is a parking lane and the turning car isn’t cutting off the closer one, then the closer one is still hiding approaching bicyclists from the turning one, whose driver must look to the right rear to see them as they get closer — remember, they may be traveling at speeds up to 25 miles per hour. The bikeway is outside the field of view of the turning driver’s right-hand rear view mirror. Some vehicles have no windows behind the front seat, and so the bikeway would be in a complete blind spot. I just got back from Montreal where I rode bikeways like this and it’s hair-raising with heavy two-way bicycle traffic in such a narrow space. I also had repeated conflicts with motorists turning across my path, using intimidation to try to make a gap for themselves in the stream of bicyclists. It’s safer to ride on 36th street just as it is now, and a bicycle boulevard would be better choice yet, especially for slower and more timid bicyclists. As John Schubert says in his comment on the blog post, there are better ways to make bicycling inviting.

The proposed design isn’t about improving traffic conditions, for bicyclists or anyone else. It’s about a social agenda: creating the appearance of safety for naive bicyclists to increase bicycle mode share, and making motoring more difficult. Actually, motorists would instead use the smaller parallel streets. Elimination of parking on one side of the street to create the bikeway is unlikely to be popular with residents. Snow clearance also is difficult with barrier posts and parked cars in the middle of the street.

The Montreal bikeways are the subject of a widely-publicized research study claiming a safety advantage, but the study has been demolished, see http://john-s-allen.com/reports/montreal-kary.htm

Posted in Bicycle facilities, Bicycling, Cycle tracks | Tagged , , , , , | 1 Comment

Fatality on Montreal cycle track

Posted on August 10, 2012 by jsallen

As reported in a Montreal Gazette article, a Montreal cyclist was killed on July 24, 2012 when traveling in a two-way cycle track at the location shown in the Google Street View image below. The cyclist entered the intersection from the same direction as the red-shirted cyclist shown in the Street View. A large box truck turned right from the location of the gray car in the foreground. According to witnesses, both had the green light. The trucker was required to yield to the cyclist.

Location of fatal truck-bicycle crash in Montreal

Location of fatal truck-bicycle crash in Montreal

Responses were diverse. A commenter on a Montreal blog identifying himself as BrunoG posted one (here in my translation from the French) which I think especially hits the mark:

I don’t want to sound like a chronic complainer, but I think that bidirectional cycle tracks on one side of the street add a particular element of danger. Because the path was bidirectional, the cyclist was riding opposite the direction of the truck, on the right (from the trucker’s point of view) — that is, opposite the direction of traffic (again, as seen from the truck). Like anyone who turns right, the trucker had to have the automatic reflex to shift his attention between right and left, close to the truck: to the left to be sure that he would not run over a pedestrian who might be crossing against the red light; to the left ahead to be sure not to collide with a car or truck coming from the opposite direction and possibly turning left and cutting across in front of him; and on the right next to his truck so as not to run over a pedestrian who might be crossing on the green light. But he probably didn’t look ahead and to the right, because he didn’t expect that a cyclist would arrive traveling opposite traffic. (He nonetheless had the duty to do that, as the path is bidirectional, but he didn’t do that because intersections with bidirectional cycle tracks probably represent less than one intersection in 10,000 in Montreal.)

Personally, I feel safer in the street, riding in the same direction as traffic, than on a bidirectional cycle track where I risk death at every intersection (the path on Rue Rachel being an off-the-charts example of the danger of these paths).

What I find especially distressing is that someone has died because of the inherent danger of an urban accommodation which was thought to be safe. I extend my greatest sympathy to those who were close to the victim.

Another cyclist, YULavélo, posting in the same thread, merely expressed sadness:

This accident affects me unlike those in earlier months and years, because this is a location I pass through every week at the same hour of the day. Because it could have been me, or I could have learned, on returning from work, that it was my partner. That’s what I think about. That someone, somewhere, might have learned of this through the media: that a son, brother, friend, boyfriend died riding on a cycle track, on the green light, wearing a helmet, going to work. A great sadness overcomes me when I think about this. That life is such a fragile thing, so horribly fragile, that it can end, tomorrow, on the corner of Christophe Colomb and Mistral, on a route which he may have known by heart, as he accelerated, on the green light, in the cool air of an early July morning, with light traffic.

The question of the responsibility of the trucker doesn’t come up, as we now have a no-fault system whose only purpose is to empty the courtrooms, a no fault system which is a reflection of the vast, great era of impunity in which we live, an era of every man for himself and winner takes all.

And even if he was responsible and is recognized as such, this does not put back the cyclist, this brother, boyfriend, friend, lover, worker, on his mount, in the morning light, in his little pleasure of going to work by bicycle.

I am sad, and the stupid commentaries on the Web sites where the news was posted– whether on the right or on the left, are only background noise which doesn’t even touch on that sadness.

The “stupid commentaries” referred to here are on the right, hatred of cyclists and on the left, recriminations against motorists.

Ian Brett Cooper, in a comment on the Gazette article, pointed out some factors which may have contributed to the crash:

At the time of the accident, the sun had just risen and was directly in front of the driver. The cyclist was in the sun’s glare and as he approached the intersection, he was shielded from the driver’s view by signs on the traffic light [pole].

[Update August 11, 2012: If you click on the Google Street View image to enlarge it, you’ll see that the compass rose has the trucker heading southeast; in July, the sun rises north of east. The signs could easily have hidden the cyclist, though. If the trucker was steering left to clear the corner, the signs would have produced a blindspot moving forward along the cycle track. Another oddity of this “protected” cycle track is the wide driveway entrance which crosses it after the intersection. A vehicle entering or leaving the driveway at the right time could have concealed the cyclist, and so could another vehicle proceeding through the intersection ahead of the truck.]

My friend Khalil Spencer commented in an e-mail:

To a significant degree, cycletracks operate similarly to sidewalk cycling, and have many of the inherent risks vis a vis motor vehicle traffic. If done correctly, the thru bicyclist and turning truck driver would probably have separate green light cycles similar to a protected pedestrian crossing. Sadly, both the cyclist and truck driver apparently had the green. Cyclists are supposed to be “protected” from motorists by the cycletracks. But the only way to protect at an intersection is to either design so there are not conflicts (not sure how to do that) or with the intervention of an administrative device such as a protected light cycle.

I replied:

Conflict points in intersections can’t be eliminated, but they can be reduced in number and in difficulty. That is what the conventional rules of the road are designed to achieve. Designs which send traffic into an intersection from unusual and unexpected directions at unexpectedly high speeds have the opposite effect.

The number of conflict points is lower on a street with fewer lines of traffic. Actually, this works to bicyclists’ benefit because a travel lane which can only accommodate one line of motor traffic can accommodate two or three of bicyclists. In that way, narrow local streets which aren’t suitable for through travel by motorists can serve well as through bicycle routes.

Conflicts can be managed by controlling the type, volume and speed of traffic. That’s why we have main streets, Interstate highways, bypasses and truck routes as opposed to in-town shopping streets, residential streets, bicycle boulevards and preferred bicycle touring routes…

I think that Montreal will begin to get a handle on its problem when it decides to convert one of the narrower east-west avenues through downtown (I’d vote for the Boulevard de Maisonneuve) into a bicycle boulevard where bicyclists and slow, local motor traffic operate according to the standard, uncomplicated rules of the road. A bidirectional cycle track is the antithesis of this approach, because it adds conflicts, complexity and confusion. The fundamental assumption underlying it is that motorists can be subjected to and held responsible for new and unusual task burdens in order to protect the bicyclist, who is a helpless victim incapable of operating according to the rules of the road. To be sure, this correctly describes children, and part of the problem is the idealistic but unrealistic concept that children should be able to travel all around urban areas safely by bicycle. Adding to the appeal of the bicyclists-as-children approach is that the typical Canadian or U.S. adult is stuck in a state of arrested development, never having cycled since childhood.

There are some protected signal phases in Montreal. The bicycle phase of the signals is so short that they are widely ignored. The person who described this situation to me was on a group ride to inspect those facilities, and told me that he learned some new and unpleasant words in French when his waiting for the light blocked the other cyclists from proceeding.

Posted in Bicycling, Cycle tracks, Sidepaths | Tagged , , , , , , , , , , , , , , , | 8 Comments

About Grant Petersen’s book, Just Ride

Posted on August 1, 2012 by jsallen

Just Ride, by Grant Petersen

This post is a review of Grant Petersen’s book Just Ride, partly in response to a New York Times review.

The basic premise of Petersen’s book is that racing culture is bad for bicycling.

My main goal with this book is to point out what I see as bike racing’s bad influence on bicycles, equipment and attitudes, and then undo it.

I agree in large part, but by no means completely.

I rode a bicycle in everyday clothes for transportation years before I took up bicycle touring and joined a recreational bicycle club. It was several more years before I first wore the much-derided spandex outfit for my tours and club rides.

So, I live in both worlds. I do think that some elements of racing technique and equipment are useful to everyday cyclists — especially concerning nutrition, how to propel the bicycle efficiently, and how to maintain it. On the other hand, faddish imitation of racers leads to some very poor choices. A fiendishly expensive, fragile racing bicycle buys the typical club rider a couple percent greater speed on a ride with no prize at the finish line. Hello, hello, you’re being taken for a ride! The bicycle industry has discovered how to churn the market with yearly model changes and planned obsolescence! It’s like choosing a Ferrari when a Toyota Corolla would be much more practical — except that a more powerful engine isn’t part of the package.

When rain starts during a bike-club ride, why must I be only among the 5% of participants who have a bicycle with fenders — or that even will accept fenders?

I have a few points of disagreement with Petersen, and the Times reviewer. About only wearing a helmet at night: it’s your choice to make, I hope. I’m not in favor of mandatory helmet laws. On the other hand, examples should be sufficient to make the case for helmet use. (A longer discussion is here.) I’ve had to replace three helmets so far in my bicycling career. All of the crashes were during daylight hours. Bicycle gloves, too, are very nice if you are going to have to put a hand out to break a fall. And a rear-view mirror? I don’t think it should be required by law, but I find mine highly useful when interacting with motorists, and with other cyclists on group rides. Actually, the Times reviewer gets this wrong — Petersen recommends mirrors. But the ones I like best attach to a helmet! (My take on mirrors). I use walkable cleated shoes, too. Disparaging practical and effective equipment doesn’t play in my book.

Petersen states that a bicyclist needs only 8 gears — somewhat in jest, giving vague (and charming and humorous) descriptions of them. Here, as elsewhere in his book, Petersen gives simple and direct advice, poking a finger at silly fads, while avoiding details that would bog down his presentation. That’s good as far as it goes, but gearing requirements depend on the cyclist, ride purpose and location. I know that Petersen knows this, based on the way he equips the bicycles he manufactures (practical, sensible, expensive but good value for money) . Most have more than 8 gears.

Petersen gives no coherent or comprehensive advice on how to ride in mixed traffic, though he describes something which is a little bit like “control and release” lane usage. Going into detail would, again, bog him down, though in this case, I get the impression that he may not be an expert on the topic.

All in all though, I really like this book. It’s refreshing. Its common-sense perspective is all too rare. And it’s a lot of fun to read, too.

Save

Posted in Bicycling, Books, Reviews | Tagged , , , , | 6 Comments

Amsterdam, cycling paradise?

Posted on June 24, 2012 by jsallen

The caption on YouTube:

Things I see on the streets and canals of Amsterdam. Shot on my Galaxy S2 phone. This guy was having trouble driving his tiny van down the bike lane (which he has a right to do, by the way). But nothing was going to stop him, even losing a bit of his own van!

The caption on YouTube:

Many people don’t realize that the “bike lanes” in Amsterdam aren’t just for bikes. They are also used by motorbikes and small cars. Space is at a premium and “just squeezing through” is the norm. It can be quite unnerving for those of us accustomed to having a 10-12 foot lane to ourselves!

Here’s a quick peek at just a few of the motor vehicles that I encountered while riding around town today in the bike lanes and cycle tracks of Amsterdam.

Posted in Bicycling | 17 Comments

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

Posted on June 15, 2012 by jsallen

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 a rearward view. We rode safely, and mostly by not using the special bicycle facilities.

Some highlights:

  • The block pavers and 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 accommodating 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…

Here is an article by the landscape architecture firm patting itself on the back for the 2009 reconstruction: https://web.archive.org/web/20131207021731/https://landscapeonline.com/research/article/15317

Posted in Bicycle facilities, Bicycling, Bike box, Bike lanes, Cycle tracks | Tagged , , , , , , , , , , , , , , , , , , , , | 6 Comments

M. Kary’s review of the Lusk et al. Montreal bikeway study — A compendium of errors and omissions, or: What is not in this article

Posted on June 6, 2012 by jsallen

Montreal resident, cyclist and mathematician M. Kary has reviewed the study by Lusk et al. of Montreal’s two-way one-side of-the-street barrier-separated on-street bikeways.

The study by Lusk et al. purports to show that the bikeways are 28% safer than riding on comparable streets without the bikeways. Kary points out a number of serious methodological and factual errors which, he contends, invalidate that conclusion.

Kary’s review is available in two formats: the PDF version looks nicer, especially when printed on paper. The HTML version is better for viewing in an Internet browser.

The review is heavily annotated and is supported by a large number of photographs. Each photo caption includes a link to a Google satellite view or street view, to pinpoint the location.

Here are a few quotes to convey the flavor of the review.

Rachel between St Urbain and Marquette

The authors list this path segment as being 3.5 km long. In fact it is approximately 1.7 – 1.8 km long, and thus has approximately twice the rates of injuries and crashes per kilometre given by Lusk et al. (The authors need to explain how they obtained the lengths they give for all their path segments.)

Construction of the reference and intervention samples

…Since presumably the authors do not count incidents occurring to cyclists travelling along the path but in the terminating intersections, using short path segments as the authors do also lowers the overall number of intersections per kilometre, making for a comparison more favourable to the paths. (Example: for block lengths of 200 m, a 1 km path without the terminating intersections would have incidents resulting from 4 intersections per kilometre, while a 5 km stretch of the same path would have incidents resulting from 4.8 intersections per kilometre— a 20% increase.)

Crash rates described as injury rates

The “What this study adds” box incorrectly compares the (incorrectly calculated, see sections 1.1 and 1.3) injury rate of 8.5 per km reported by the authors with a range of 3.75 to 67 supposedly reported elsewhere. In fact the latter figures are crash rates, not injury rates.

Figure 13: René Lévesque at Maison Radio-Canada

In 1990. renowned CBC journalist and producer Joan Donaldson attempted to cross this two-way path to get a taxi, and was struck down by a cyclist coming from her right. She remained in a coma for at least six months, could not speak at all for three years, and was left permanently brain-damaged and quadriplegic. The cyclist was uninjured. Donaldson died in 2006 from extended complications of the accident. Authors’ method does not count such injuries, for not being to a cyclist.

Enough. Please read the review.

Posted in Bicycling | 13 Comments

Review of December 2011 fatal truck-bicycle collision at MIT, Cambridge, Massachusetts

Posted on May 20, 2012 by jsallen

The MIT student newspaper, The Tech, has obtained police reports about last December’s fatal bicycle-truck collision at Massachusetts Avenue and Vassar Street in Cambridge. I have reviewed the story in The Tech and the police reports, and posted my review on the Cambridge Civic Forum blog.

Posted in Bicycling | 4 Comments

Two ways to cross a street

Posted on April 25, 2012 by jsallen

Cyclist Richard Moeur stars in this video comparing the time it takes to cross the same intersection as a rolling pedestrian, or as a vehicle operator. A light rail train, a homeless person and a number of motor vehicles also make appearances. Popcorn time…well, actually it only runs for 5 minutes.

Posted in Bicycling | 4 Comments

About the Austin colored bike lane marking report

Posted on April 15, 2012 by jsallen

Please read the Austin, Texas colored bike-lane report, Effects of Colored Lane Markings on
Bicyclist and Motorist Behavior at Conflict Areas in connection with this review of it.

My comments:

In the Executive Summary:

The report says:

Conflicts are common on facilities where a motorist must cross a bicycle lane in order to access a right turn bay and where highway exit ramps cross major arterials that have a bicycle lane.

A conflict is a situation in which one road user must take abrupt action to avoid a collision with another. Colored markings are sometimes used to mitigate the problems with what can accurately be described as conflict zones: zones where unusual yielding rules apply, where sanctioned movements require looking in unusual directions, and/or where sight lines are restricted.

On the other hand, colored markings are sometimes used in what I would describe as merge zones, or crosswalks, or bike lane extensions across ramps — places where the motorist or bicyclist must yield right of way according to normal rules, with no unusual impediments.

In other reports, the researchers have describe route choices as “avoidance maneuvers” and merges into an adjacent lane as “encroachments”. Here, they elevate normal traffic maneuvers to “conflicts.” Conflicts may indeed sometimes occur during normal traffic maneuvers, as a result of mistakes in driving, but that doesn’t elevate the locations of these conflicts into “conflict zones”.

Examples of both normal traffic movements and conflict-generating ones are discussed in this report. The distinction deserves to be made clear.

All in all, the researchers’ repeated use of terms describing hazardous and unlawful maneuvers to describe normal and reasonably safe maneuvers raises serious questions about their understanding of the traffic laws, and traffic operation.

Quoting again:

For this study, safety was defined along the following lines:

  1. the bicyclist used the bicycle lane to approach the conflict area,
  2. the bicyclist used the bicycle lane to negotiate the conflict area,
  3. the motorist yielded to the bicyclist when crossing the colored lane area, and
  4. the motorist used a turn signal when crossing the conflict area.

Only the last two of these four criteria relate clearly to safety. Whether the first two do depends on whether the markings are properly located considering traffic conditions at the time and place.

To ensure that the data collected reflects the effectiveness of the treatment alone, no educational or outreach campaign was conducted.

This issue poses a legitimate quandary. Markings must be understood to be effective. The colored paint here is between ordinary bike lane markings, and that makes their intention clearer. Still, it would have made the most sense to compare the effectiveness of the markings without, and then with, an educational campaign.

However, the colored paint in this study was accompanied by installation of “yield to bikes” signs, which produced a similar conflation of results as an education campaign would. There was no phased installation, and so it can not be determined to what extent the change in behavior resulted from the signs or from the paint.

In the section Background:

Figure 1 in the report shows a situation in which bicyclists taking the route shown have to yield to motorists in the interest of safety, due to a restricted sight line, and not to defeat the purpose of the on-ramp in allowing motorists to accelerate into the flow of traffic. Instead, the motorists are required to yield to the bicyclists, as at a crosswalk.

Research in the U.K. (reported to me by John Franklin) has shown a problem with fatal collisions between motorists entering from high-speed ramps — looking back to merge into traffic — and bicyclists who continue in the normal through-travel lane position. I will not condemn the routing shown — but for the reasons I have given, it does require bicyclists to yield.

In the photo, I also note that there is a sidewalk, but there are no crosswalk markings. What expectations does this treatment create, in connection with the bold bike lane markings? That motorists should stop and look only upon reaching the bike lane? That pedestrians should use the bike lane as a crosswalk?

In the section Site Descriptions

Figure 4 — shows that all of the three lanes on Dean Keeton cross ramps at a very low angle, worsening sight conditions for bicyclists and greatly increasing their crossing times. Compare with the crossing on Naito Boulevard in Portland, Oregon — which has other issues but which crosses at a right angle.

Figure 7 — This shows a more conventional vehicular routing of bicyclists, straight through to the left of an off-ramp. I find it odd that the green paint begins partway into the merge zone rather than at its start.

In the section Experimental Design

The same four criteria for safety are repeated, and again, only the last two relate directly to safety. It could be argued, for example, that at least the slower and more timid bicyclists are safer riding down the right side of the ramp on San Jacinto Boulevard, turning left and yielding to motorists. As motorists are generally traveling faster than bicyclists and approaching from behind, it can be argued that the last criterion givwen, motorist used turn signal, is irrelevant, because bicyclists would not see the signal. An actual measurement of safety would require counting conflicts, in the usual meaning of the term — abrupt braking or swerving either by a bicyclist or by a motorist.

In the section Terminology

The definitions here are generally good, including, this time, a correct definition of “conflict”. However:

If the motorist accelerated to cut off the bicyclist while the bicyclist was in the conflict area or the bicyclist yielded to the car during a yielding event, the yielding event was not described as ‘car yielded to bicyclist’.

The incorrect term ‘conflict area” is used inside the definition of “yielding event”, and there are not separate categories for motorists cutting off bicyclists, and bicyclists yielding to motorists. Not every motor vehicle is a car.

Illegal event – An event was recorded as illegal if the bicyclist acted in a way that qualified as an event, but also acted illegally or very unsafely.

What if the motorist acted illegally?

In the section Results

Tables 1 and 2 show very little difference in bicyclists’ behavior.

Tables 3 and 4 show an increase in yielding behavior and turn signal use by motorists, but the sample size is very small. Note that yielding at the facilities provided is different from that on San Jacinto Boulevard, because motorists are required to slow or stop in order to yield, rather than only to time a merge. At the on-ramps, there is only one way to go, and at off ramps, motorists are coming from behind bicyclists and supposed to yield to them, so it is unclear to me just what the use of turn signals achieves for bicyclists, Signals are, however, useful when merging from the ramps into faster traffic.

The remaining tables show mixed results and minor differences in behavior, generally somewhat improved except for Table 9, which shows a steep reduction in motorist yielding behavior but with an extremely small sample size.

In the section Conclusions and Recommendations

The conclusions in favor of the painting appear overstated to me, and particularly in the light of installation of signs at the same time.

References:

None of the four references is directly to a study of a similar treatment — three of the four relate to generalities about what encourages people to ride bicycles and one is about integrating bicyclists into a pedestrian campus. That is a bit surprising because a study of colored lanes, the Portland blue lane study,

(FHWA version); (Version on Portland, Oregon site)

has not only been published but also is referred to in the text of the report. (page 8, second paragraph). Considering the number of European countries referred to in the Austin report, I would not be surprised if European studies also exist.

Posted in Bicycling | 1 Comment

About the Austin Bicycles May Use Full Lane report

Posted on April 14, 2012 by jsallen

This is a review of an Austin, Texas Bicycles May Use Full Lane (BMUFL) sign report.

All in all, I consider this a useful report, though it has serious weaknesses. The finding that the BMUFL sign improved motorist behavior is encouraging, though the improvement was not as great as to be hoped.

That many bicyclists did not take advantage of the signage is to be expected, for three reasons which I can discern:

  • many are fearful of riding on roads with narrow lanes in any case;
  • there was no educational campaign; and also,
  • the signs are primarily directed at motorists.

It is not surprising that the shared-lane marking study conducted at the same time as this study (and which I also have reviewed) showed more success in changing cyclists’ behavior, because shared-lane markings are directed at bicyclists.

I would venture that wide acceptance of cycling on narrow urban roadways requires education; also, particularly for child cyclists, diversion of through motor traffic to other roadways using a “bicycle boulevard” approach like that in Berkeley, California. I would be most interested to see this tested in Austin, which, like Berkeley, has a street grid amenable to such treatment.

In the executive summary, I note the following:

Additionally, safe motorist behavior was defined by two factors: (1) motorists gave adequate space to bicyclists when passing and (2) motorists did not encroach on adjacent lanes when passing.

I can’t make sense of this. That is to say, it is hopelessly confused. The lanes in this study are 11 feet wide, too narrow for a bicyclist and motorist to share safely side by side. If a lane is too narrow to share, then motorists can only overtake safely by merging their vehicles partly or completely into the next lane. Where it is legal to merge into the next lane, as on both streets where the experiment was conducted (four-lane two-way streets), then merging is not “encroaching.”

In the section on Experimental Design, I note that the lateral position of bicyclists was measured at their wheel track, and that of motorists, at the right side of the vehicle’s right-side wheels — see Figure 9 in the report. This measurement is meaningless. Bicyclists’ handlebars extend as much as 12 inches either side of the wheel track, and motorists’ rear-view mirrors may extend several inches to the right of the wheels, and more for large trucks and buses.

In the list of definitions, the term “avoidance maneuver” is used incorrectly, as it is in the bike box report, which I also have reviewed:

Avoidance maneuver An avoidance maneuver was recorded whenever a bicyclist rode outside of the lane (e.g. rode on the sidewalk or cut through a driveway to turn).

This is a choice of route, not an avoidance maneuver, which is an emergency maneuver to avoid a collision.

There are other confused definitions:

Incomplete passing event – An incomplete passing event was recorded when the motorist passed a bicyclist without changing lanes.

This is an in-lane pass, not an incomplete pass. An incomplete pass would occur if a motorist initiates a pass and then decides not to pass.

Encroachment – Encroachment was recorded when a passing motorist occupied two lanes while passing.

This is not encroachment, as already mentioned. It is a straddle pass, as defined and named accurately by Dan Gutierrez and Brian DeSousa, see citation below.

In the section on Results —

The bicyclists’ change in lane position is statistically significant due to the large number of data points. In spite of what the report says, it is operationally insignificant, amounting to only three or four inches. The change in clearance between motor vehicles and bicyclists due to motorists’ different position, on the other hand, is significant both statistically and operationally. (But do remember, the bicyclists’ position is measured at the wheel track, and the motorists’, at the right side of the right-side wheels. Actual clearances are smaller than those described in the report by about 1 1/2 feet. That makes the differences more significant operationally.)

Accounting for this, motorist lateral clearances from the curb and from bicyclists during passing events (Figures 12 and 13) are scary indeed. Clearances following installation of the signs are not as tight, though they also could be greater. Bicyclists’ not claiming the lane invites the close passes.

Quoting:

Regarding motorist behavior, it is interesting to note that the ratio of passing events to non-passing events decreased significantly, while the proportion of passing motorists who encroached while passing increased. These results lend themselves to the hypothesis that as bicyclists took a stronger position in the lane, the motorists who did choose to pass found themselves taking a stronger position in the lane that caused them to encroach on the adjacent lane.

In spite of the incorrect terminology, this result confirms the result of Gutierrez and DeSousa’s research (see citation below)..

And quoting again:

Regarding bicyclist behavior, the implementation of the “Bicycles May Use Full Lane” signs did not discourage sidewalk riding. It is uncertain whether the bicyclists who avoid the motor vehicle lane are regular commuters and recreational bicyclists who prefer to ride outside of the motor vehicle lane or if they are simply neighborhood children or inexperienced bicyclists. Regardless of their experience level, it appears that the addition of signs did not significantly change the proportion of bicyclists who use the motor vehicle lane.

The data analysis could not identify different categories of adult cyclists but I don’t see why it couldn’t identify children. The researchers use more incorrect terminology, extremely obtuse at that. How is a lane with signs indicating “Bicycle may use full lane” a “motor vehicle lane”?

The finding that cycling on sidewalks increased greatly after installation of the signs on Cesar Chavez boulevard begs for an explanation. I don’t see how installation of the signs would affect this one way or another.

In the section Conclusions and Recommendations:

I quote:

It should be noted that encroachment is only dangerous when there are vehicles present in the adjacent lane, and this study did not note whether or not this was the case.

What is being described is normal changing lanes to overtake a slower vehicle. It is being described as dangerous and as encroachment. This is bizarre.

In the section on References:

None of the references is to another study of the BMUFL sign, as this is the first one. However, Gutierrez and DeSousa’s study of overtaking clearance deserves attention as a study of the effect of bicyclist lateral position. These researchers also developed the accurate and values-neutral terminology, in-lane pass, straddle pass, lane-change pass, which compares very favorably with the confused terminology of the Austin report..

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