Category Archives: Bicycle facilities

Monsere, Dill et al. — Not Yet a Review, But…

M. Kary, who prepared a review of the Lusk et al Montreal study, has had a preliminary look at the Monsere, Dill et al. study of barrier-separated on-street bikeways (“cycle tracks”) which the bicycle industry lobby PeopleforBikes is promoting as demonstrating their safety. Dr. Kary has given me permission to publish his comments here.

An Introduction To and Overview Of:
Monsere C, Dill J, et al. (2014) Lessons From The Green Lanes: Evaluating Protected Bike Lanes In The U.S. Final Report, NITC-RR-583

To begin with a platitude: traffic accidents are rare events. The totals are large only because the overall volumes of exposure are huge. Therefore, if considering safety in terms of outcomes rather than the underlying mechanisms of operation, any facility, no matter how poorly designed, will appear safe if examined over a short period of time.

But collecting data over a long period of time has its disadvantages too: not just cost and delay, but also the averaging, and therefore blurring, of the effects of various changing causes and circumstances. Nor does it work at all for facilities that are yet to be built. In response to these problems, engineers developed the methods of traffic conflict analysis. They can be seen as based on the following logical and kinematic necessities. First, in order for a collision to occur, the vehicles involved must eventually get on a collision course. Second, in order to get on a collision course, they must first get on a near-collision course. On the other hand, not all vehicles once on collision or near-collision course do end up colliding: their operators make course corrections and avoid that outcome. Such potentially dangerous but often ultimately safe trajectories, i.e. traffic conflicts, occur much more frequently than actual collisions, deaths, or injuries. If there exists a suitable relationship between the former and the latter, then conflict analysis can be used to study road safety at reduced cost, with better timing, and even via simulation modelling of facilities that have been designed but not yet built.

The theory and practice of conflict analysis for motor vehicles has been developed over something like a half a century of research. This has evolved to quantitative methods using not just traffic cameras, but also instrumented vehicles, automated data extraction, and theoretical concepts such as time to collision, gap time, gap acceptance, post-encroachment time, and many others. There is no such corresponding body of research for bicycles. Even if there were, it could never be as important to bicycle or pedestrian deaths and injuries as it is for the occupants of cars and trucks: for example, the latter vehicles never topple over at stops or just slip and fall, so that their occupants fracture an arm or strike their heads on a curb. In fact the majority of bicyclist injuries, even those requiring hospitalization, apparently involve only the bicyclist, making conflict analysis entirely or at least largely irrelevant to them.

On the other hand collisions with motor vehicles are major factors in cyclist deaths and injuries, and they are what cyclists worry most about. And even apparently bicycle-only crashes can be provoked by e.g. general fears or specific intimidations, or avoidance manoeuvres leading to loss of control. Thus there are also dimensions of traffic conflicts applicable to bicycling, but either inapplicable or less so to motor vehicle-only conflicts. Nor is every conflict visible or strictly kinematic: consider for example the effects of sudden and loud horn honking or engine revving.

With these fundamental limitations in mind, obviously traffic conflict analysis is a promising method for investigating important aspects of bicycling safety. The theory needs to be developed, so we can figure out what constitutes a high or low rate of conflicts, what types of conflicts figure what way into which accident types, and how vehicle operators and pedestrians cope with them, such as through hypervigilance, or avoidance of the area and thus diversion of problems to a different one.

Not only does the theory need to be developed, but also the methods of data extraction and analysis: the subjective review of traffic camera recordings, typically of low quality, is a mind-numbingly tedious, labour-intensive and error-prone task, that does not scale well.

The work of Monsere et al. (2014), Lessons From The Green Lanes: Evaluating Protected Bike Lanes In The U.S., should be considered a pilot project in this effort, although the authors themselves do not describe it as such.

Monsere et al. aimed to address six questions:

  1. Do the facilities attract more cyclists?
  2. How well do the design features of the facilities work? In particular, do both the users of the protected bicycle facility and adjacent travel lanes understand the design intents of the facility, especially unique or experimental treatments at intersections?
  3. Do the protected lanes improve users’ perceptions of safety?
  4. What are the perceptions of nearby residents?
  5. How attractive are the protected lanes to different groups of people?
  6. Is the installation of the lanes associated with measureable increases in economic activity?

Apart from noting that, as with most sociological research, their survey response rates were dismally low (23-33% overall, counting even only partially completed surveys as full responses), to produce a socioeconomically skewed sample (e.g. the bicyclists being 89% white, 68% male, 82% having at least a four-year college degree, and 48% with annual incomes over $100,000)— this overview of their work considers only the first part of their question No. 2.

Monsere et al. installed video cameras along short bicycle sidepaths (“protected lanes”, “cycle tracks”) constructed between approximately the summer of 2012 and the early summer of 2013 as part of the Green Lanes Project. These were in four U.S. cities, San Francisco (two 0.3 mile paths), Portland (one 0.8 mile path), Chicago (0.8 and 1.2 mile paths) and Washington (a 1.12 mile path; no cameras were installed in Austin, although sociological surveys were conducted there). They did their video recording chiefly at intersections, six in these four cities in the summer and fall of 2013. This was then presumably while the users were still in a cautious or exploratory state, as they got used to the new facilities.

Only 12-18, or in one case 20, independent hours of video were analyzed from each intersection. As each intersection examined was given a unique treatment, results cannot easily be pooled. These are very small numbers.

(This makes for substantially less than 120 hours total. The authors seem to say they analyzed 144 hours of video at intersections. This would mean that some of this total came from multiple cameras examining the same intersection at the same time. The authors do show frame captures from some of their cameras. This observer would find it difficult to correctly identify the conflicts from the views on display.)

As noted following the opening platitude, any facility, no matter how poorly designed, will appear safe if examined over a short enough period of time.

The six facilities examined were all so new (less than or little more than a calendar year old) that there were no injury or death data available for them. (For comparison, the entire city and island of Montreal, with all its thousands of intersections, averages of late about five cyclist deaths and 25-50 police-recorded serious cycling injuries per year.) Thus, there would not have been a way to use even many more hours of recording to examine for any relationship between the surrogate outcomes (conflicts, violations or errant behaviours) and the outcomes of most interest, deaths and injuries.

Further, as this was neither a before-after study nor a comparison with standard intersections, there is no way to know whether the numbers of observed conflicts, violations, or errant behaviours, were themselves high or low.

As to the actual results from this pilot project, the much touted headline was that there were only six minor conflicts found, out of nearly 12,900 bicycle movements through intersections. The most basic problems with this headline are:

1. It is the wrong comparison. The conflict rate has to be the number of conflicts divided by the number of occasions where at least two users capable of conflicting are present, e.g. a bicycle and at least one other bicycle, pedestrian, or motor vehicle. Thus the authors give figures of 7574 turning motor vehicles, but only 1997 turning motor vehicles with bicycles present. The corresponding conflict rates (which they normalize by the products of bicycle and motor vehicle movements, not by the numbers of bicycle movements alone) they give for the individual intersections therefore vary by factors of approximately 3 to 10, depending on which figures are used.

2. Six is the total of observed “minor” conflicts, not the total number of observed conflicts. There were also 379 “precautionary” conflicts with motor vehicles, 216 with pedestrians, and 70 with other bicycles.

3. Besides conflicts, there were numerous violations or other errant behaviours: e.g. 9-70% of bicycles and 7-52% of turning motor vehicles in the various intersection designs used the lanes incorrectly, 1-18% of turning motor vehicles in the various mixing zone designs turned from the wrong lane, 5-10% of motorists turned illegally on red arrows at intersections with bicycle-specific signals, and 7-23% of bicyclists disobeyed their signals.

4. Without any theory or model of how any of these occurrences or their frequencies relate to death, injury, or property damage, and without any before-after or non-sidepath comparison data— not to mention, with the very small numbers of observation hours— there are almost no safety implications, positive or negative. The only concrete result is that one of the local authorities apparently deemed the problem of motor vehicles turning from the wrong lane (18%), straddling lanes (another 17%), or entering the turn lane early (15%) to be so severe that they later removed the intersection treatment and replaced it with another design (at Fell and Baker in San Francisco).

5. The sociological surveys tell another story: one-third of all bicyclists surveyed said they had been involved in at least one near collision on the paths, while 2% experienced an actual collision. 23% had a near collision with turning cars, 1.8% an actual collision with turning cars; 19% a near collision with a pedestrian, and 0.4% an actual collision with a pedestrian.

In short: this is an interesting pilot project, whose methods are impractical for the amount of data collection needed for meaningful safety results. Even with better methods, conflicts are only one facet of the bicycling, and overall safety picture; while road designers and road users, whether bicyclists or motorists, have to consider more than just safety. Convenience, transit time, cost, and greenhouse gas emissions also matter. A cycle track that, like the downtown de Maisonneuve track in Montreal, lies largely dormant in the winter, but delays motor vehicle traffic in the winter and ties it up spring, summer and fall, will be of no help in reducing CO2 emissions. The much touted headline results from this study are selective, overblown, and misleading. Any facility will appear safe if examined over a short enough period of time, and surely 12 to 20 hours each is short enough

Godzilla’s toothpaste decorates Seattle bikeway

A new bikeway has recently opened on Broadway in Seattle, Washington state, USA.

Someone has posted a video of a ride on the newly-opened bikeway.

(To get a better view of the video, click on “YouTube” and open it up full-screen.)

This is an uphill ride, very slow in most places. Traffic was light on the street, and even lighter on the bikeway. It will be interesting to see how the situation develops when traffic is heavier.

The bicyclist who made the video is clearly aware of the hazards, as he or she repeatedly checks for turning traffic before crossing intersections. Others might be more naive.

What most catches the eye though about this installation is the “Godzilla’s Toothpaste” barriers between the bikeway and parking spaces — an artistic touch, to be sure, though also a collision hazard, and sure to be pummeled by cars pulling into parking spaces. The toothpaste is visible a few seconds from the start of the video and also later.

As described by Seattle cyclist Joshua Putnam, the installation of the bikeway followed from a series of events, like a chain of dominoes falling over, except that some the dominoes were bicyclists. The first of these events was installation of a light rail line in the street. Then, bicycle crashes became much more frequent.

Light rail lines in streets are a serious hazard for bicyclists, from wheels’ getting caught in the flangeway, and from bicyclists’ having to choose their line of travel to avoid that risk. The problem is worsened by the tracks’ curving over to the edge of the street at stops — necessary so there can be a raised platform and wheelchair access.

To address the hazard it created with the trolley tracks, Seattle installed a two-way, one-side-of-the-street bikeway, on this two-way street. Such bikeways pose problems anywhere, due to the increased number of conflicts and unusual movements at intersections — but also much of Broadway is steep, and bicyclists traveling opposite the usual flow of traffic on the bikeway are going downhill. Crossing an intersection or driveway from right to left on the near side has been well-established as highly hazardous.

Before the trolley tracks, before the bikeway, bicyclists could travel downhill as fast as the motor traffic. Now, the safe speed is hardly more than walking speed, and with repeated checks for crossing and turning conflicts. As is the usual practice, large swatches of green paint have been spread on the street to demarcate zones where bicyclists and motorists operating according to their usual expectations are concealed from each other until too late to avoid collisions.

Motorcyclists also are at risk from the trolley tracks, but they are excluded by law from the bikeway.

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.

How not to restripe

Gordon Renkes has produced a video showing conditions following restriping at Tamarack Circle in Columbus, Ohio, USA. Here’s a Google overhead view of this rather unusual circular street. Click away the caption balloon to get a better view. You may enlarge this view, or go to the full-featured Google page by clicking on “View Larger Map under the image.

View Larger Map

The teardrop pointer is at the location of the Google Street View below, of Tamarack Circle before the restriping. (I downloaded the image instead of embedding the Google image, in case Google redoes the Street View).

Google Street view of Tamarack Circle before restriping

Google Street view of Tamarack Circle before restriping

Before the restriping, with the very wide right lane, motorists probably parked most of the way to the corner, and many cyclists probably rode in the door zone.

Here’s the video showing condition following the restriping:

The design does encourage cyclists to ride outside the door zone of parked cars. But, as the video shows, the striping confuses motorists. Among other things, the striping instructs them to right-hook cyclists. In the video, one motorist even right-hooks another. Ohio law says:

“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.”

Striping which incites violations of the law risks liability claims.

Creating right-turn pockets to resolve the problems would require removal of a few parking spaces before each entering street.

If parking were on the left at the inside of the curve, sight lines at intersections with streets at the outside would be better (though worse at driveways at the inside, and for drivers exiting parking spaces, due to the curve). A combined bike lane/right turn lane (still “experimental”) would be needed due to width limitations.

Boston Globe: Reality Check Time

The caption with the picture below in the Starts and Stops column of the Metro section of the June 17, 2012 Boston Globe reads:

Cyclists stopped for a red light in the “bike box” on Commonwealth Avenue in the Back Bay. They provide the cyclist a safe space to wait ahead of cars at traffic signals.

Photo which appeared in the Boston Globe Metro section, June 9, 2012

Photo which appeared in the Boston Globe Metro section, June 9, 2012

(The Globe story may be behind a paywall, but you can probably access it through a public library’s Web site using your library card number.)

The smiling cyclists show that this is a posed photo; the photographer evidently only thought of the large puddle in the foreground as an artistic touch. How about the car encroaching into the bike box in the background?

Well, yes, OK, waiting in the bike box might be safe — drivers are unlikely to encroach on a cyclist who is already waiting in the bike box. The problem is with getting into the bike box. The Globe columnist, Eric Moskowitz, never considered that bicyclists approaching the bike box on a red light are encouraged to swerve sharply left across multiple lanes of motor vehicles, with no way to know when the light will turn green. A waiting motorist will not see the swerving cyclist if looking to the left for traffic at the wrong moment. A tall vehicle in one lane will conceal the cyclist from a driver waiting in the next lane.

Portland, Oregon has hosted a study of bike boxes, which found that this is actually a rare problem in Portland, because cyclists are smart enough not to swerve into the bike box. Instead, if the light is red, they wait at the right curb, blocking other cyclists behind them. I saw the same thing on Commonwealth Avenue. As I said before, the Globe photo is posed.

But on the green light, there’s another problem. Bike boxes and the bike lanes which lead to them invite cyclists to overtake waiting motor vehicles on the right, risking getting struck by a right-turning vehicle. A bicyclist was right-hooked and killed in Portland, Oregon, on May 16, 2012 but apparently that news didn’t reach the Globe’s columnist, or didn’t make an impression on him. Now a letter from the City of Portland is conceding that car-bike crashes have increased at some of the intersections where bike boxes were installed. So much for the Globe’s assertion of safety.

Conscientious bicycling advocates have been warning about the “right hook” problem for decades, based on the difficulty which motorists have in looking into their right rear blindspot, while also checking the intersection ahead.

Swerving across is illegal too: here’s the Massachusetts law, in Chapter 89, Section 4A. It applies to bicyclists, the same as other drivers. Every state has a similar law.

When any way has been divided into lanes, the driver of a vehicle shall so drive that the vehicle shall be entirely within a single lane, and he shall not move from the lane in which he is driving until he has first ascertained if such movement can be made with safety.

Bicycling advocates, planners and government officials who promote bike boxes have simply chosen to pretend that this traffic law doesn’t exist, or can be ignored. Same for the limits of human abilities.

Now, I wouldn’t be fair in making this criticism if I didn’t suggest alternatives.

The one I favor is for cyclists to merge before reaching the intersection. That can be facilitated by signal timing at the previous intersection to allow cyclists to merge across when motor traffic is stopped, and a clear lane into which to merge.

Other suggestions have been to prohibit right turns, or to install special signals to warn cyclists that the light is about to change. Denver’s retired bicycle coordinator, James Mackay, has described some of the measures used in European cities.

These measures will, however, result in more delay, for both cyclists and motorists.

It may be more practical just to designate another street as the one for through bicycle traffic, My favorite suggestion at this Back Bay location would be Newbury street, configured as a two-way bicycle boulevard with a bridge over the Muddy River to connect it with the Fenway area.

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

A reader pointed me to a news story on the 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:

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.

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 ( 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”.

The Photoshop School of Traffic Engineering strikes again!

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

For background, please read the Minneapolis blog post:

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

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…

Link to my letter to Senator Scott Brown

My letter to a staffer of Senator Scott Brown about the mandatory sidepath provision in the Federal Tranportation Bill is online. Feel free to re-use it, or parts of it.

Mandatory sidepath laws, state by state

I don’t like mandatory sidepath laws for bicyclists, but I like the one in the Transportation Bill, applying to roads on Federal lands, even less.

(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 unless the Secretary determines that the bicycle level of service on that roadway is rated B or higher.

I have had a look at state laws on the Internet.

I’m pleased to report that I couldn’t find the ones which Dan Gutierrez earlier listed on his map for Colorado, Hawaii, North Dakota and Louisiana. Dan has updated his page: these laws appear to have been repealed.

The national trend has been for repeal of these laws. While the states have been repealing them, the Federal Transportation Bill, as of March, 2012, includes a provision which is more draconian than any of the remaining state laws, in that it would ban bicycles on a road even if the path is unusable. It might be called the “you can’t get there from here” law, to quote a New England expression. See my previous post for the details.

States with mandatory sidepath laws are shown in red in Dan Gutierrez's map

States with mandatory sidepath laws are shown in red in Dan Gutierrez's map

Mandatory sidepath laws, as far as I can determine, now are on the books in only 7 states: Alabama, Georgia, Kansas, Nebraska, Oregon, Utah and West Virginia. All except for Oregon require the path to be usable; the Oregon law has been explained to me as not actually having any effect, because government agencies will not take on the legal burden of having to defend paths as being safe.

Some of the laws have additional limitations on where path use can be made mandatory. See comments below. The boldface is mine.


Section 32-5A-263
Riding on roadways and bicycle paths.

(c) Wherever a usable path for bicycles has been provided adjacent to a roadway, bicycle riders shall use such path and shall not use the roadway.


Note discretionary application, and design standard and destination accessibility requirement for the paths.

O.C.G.A. 40-6-294 (2010)

40-6-294. Riding on roadways and bicycle paths

(c) Whenever a usable path has been provided adjacent to a roadway and designated for the exclusive use of bicycle riders, then the appropriate governing authority may require that bicycle riders use such path and not use those sections of the roadway so specified by such local governing authority. The governing authority may be petitioned to remove restrictions upon demonstration that the path has become inadequate due to capacity, maintenance, or other causes.

(d) Paths subject to the provisions of subsection (c) of this Code section shall at a minimum be required to meet accepted guidelines, recommendations, and criteria with respect to planning, design, operation, and maintenance as set forth by the American Association of State Highway and Transportation Officials, and such paths shall provide accessibility to destinations equivalent to the use of the roadway.


(d) Wherever a usable path for bicycles has been provided adjacent to a roadway, bicycle riders shall use such path and shall not use the roadway.


60-6,317. Bicycles on roadways and bicycle paths; general rules; regulation by local authority.

(3) Except as provided in section 60-6,142, whenever a usable path for bicycles has been provided adjacent to a highway, a person operating a bicycle shall use such path and shall not use such highway.


My understanding, based on a sicussion with former Oregon state bicycle coordinator Michael Ronkin, is that this law is never enforced, because state and local authorities will not risk ruling that a path is suitable.

814.420: Failure to use bicycle lane or path; exceptions; penalty.

(1) Except as provided in subsections (2) and (3) of this section, a person commits the offense of failure to use a bicycle lane or path if the person operates a bicycle on any portion of a roadway that is not a bicycle lane or bicycle path when a bicycle lane or bicycle path is adjacent to or near the roadway.

(2) A person is not required to comply with this section unless the state or local authority with jurisdiction over the roadway finds, after public hearing, that the bicycle lane or bicycle path is suitable for safe bicycle use at reasonable rates of speed.


Note that this applies only where signs have been posted directing bicyclists to use a path.

41-6a-1105. Operation of bicycle or moped on and use of roadway — Duties, prohibitions.

(4) If a usable path for bicycles has been provided adjacent to a roadway, a bicycle rider may be directed by a traffic-control device to use the path and not the roadway.

West Virginia

§17C-11-5. Riding on roadways and bicycle paths.

(c) Whenever a usable path for bicycles has been provided adjacent to a roadway, bicycle riders shall use such path and shall not use the roadway.