Category Archives: Bike box

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.

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…

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.

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.

The Six-Way, Washington, DC, a Second Look

The video embedded below documents a bicycle ride by the author and two companions in Washington, DC where special bicycle signals and road markings have been installed to establish continuity of New Hampshire Avenue at its intersection with U Street and 16th Street.

The video tells the story of an unusual pass through the intersection — the signal actuator somehow didn’t give us the green on the first go-round. It did on other passes.

Aside from that one quirk, the video shows the usual signal timing (though it might be different at another time of day). The most significant finding is the short time to get into the “bike box” which is located ahead of motorists’ advanced stop line. There wouldn’t be be enough time for any large number of bicyclists who had been waiting for the signal.

Several additional issues remain to be shown in other videos. Here is a preview of what they will show:

  • The bike boxes are very small, also a problem with large numbers of bicyclists.
  • Motorist encroachment into the bike boxes is endemic.
  • Some motorists misunderstand the installation to the degree that they become angry at bicyclists who use it as intended. We were buzzed on one pass by someone driving a big black SUV.
  • Probably 90 percent of cyclists passing through this intersection on New Hampshire Avenue do not use the facility as intended. Rather, most use the crosswalks — commonly going around clockwise. With the option to go either clockwise or counterclockwise, bicyclists can start across on either pedestrian phase, rather than having to wait through as much as an entire signal cycle for the special bicycle phase.

Before I actually rode through this installation, I thought that it was a particularly good one. I have a blog post expressing that opinion. That post also gives a detailed description of the installation and its history.

The installation doesn’t violate any principles of traffic theory. In particular, when used as intended, it doesn’t place bicyclists and motorists out of sight of each other and on a collision course. But as Yogi Berra, or maybe Albert Einstein, memorably said, “[I]n theory, theory and practice are the same. In practice, they are not.” This installation makes the intended movements unattractive due to the short timing and tight space. The installation also makes bicyclists wait much longer to take the intended routes than to take others — which don’t even necessarily require illegal movements. As such, this installation unfortunately is not, in my opinion, successful.

I approve of this?

UPDATE: This post gives background information on the intersection. I have now ridden through it, and my opinion of it has changed. I have another post about it, and a video. Please check them out.


The image below shows a special installation of traffic signals and markings at the intersection of 16th street, U Street and New Hampshire Avenue NW in Washington, DC. To enlarge the image so you can read the text descriptions, click on it. You also may have a look at a Google map satellite view. Then please return to this page for my comments.

16th Street, U Street and New Hampshire Avenue NW, Washington, DC

16th Street, U Street and New Hampshire Avenue NW, Washington, DC

Pierre L’Enfant and Andrew Ellicott — and let’s also not forget African-American surveyor Benjamin Banneker — laid out Washington’s streets from scratch –  in the pre-automotive 1790s. Washington’s diagonal avenues give it an openness and unique sense of place — but the resulting uneven-length blocks and multi-way intersections make for some serious headaches now. Some traffic movements are odd, traffic signals can not be synchronized efficiently…

Before the new installation, no signals in this intersection faced new Hampshire Avenue. Bicyclists would sometimes use New Hampshire Avenue for through travel, though its conflicting one-way segments made that illegal and there was no conflict-free crossing interval.

The illustration above is from a page posted by the government of the District of Columbia describing a new installation of contraflow bicycle lanes, bicycle waiting boxes and special traffic signals. At first glance, these may raise the hair on the back of the necks of people who are suspicious of special bicycle facilities treatments.

Look again. The bike boxes look odd only because they connect with diagonal New Hampshire Avenue. They are cross-street bike boxes — which bicyclists enter from the left. Bicyclists from New Hampshire Avenue enter on a separate signal phase from the motor traffic on 16th Street, rather than to creep up on the right side of motor vehicles, as with more-usual bike-box installations. Motorists do not have to crane their necks or stare into a right-side mirror looking for these bicyclists.

The cross-street bike boxes are even more conflict-free than usual. Because only bicycle traffic runs contraflow, bicyclists do not have to negotiate with any right-turning traffic when entering the intersection.

To summarize: this installation, importantly, does not violate the fundamental traffic-engineering principle of destination positioning at intersections, as so many special bicycle facilities installations do.

Or, looking at the same conclusion from a different point of view, the installation does not require or encourage bicyclists to do anything dangerous or stupid, and it offers reasonable travel efficiency considering the situation it addresses.

I am not going to say that this installation is perfect. I can see the following issues.

  • Bicyclists’ having to wait through two traffic-signal phases is inconvenient and might lead to scofflaw behavior. A “scramble phase” could allow crossing in one step and might even apply to bicyclists arriving from other directions. It would reduce the time allocated to for all the other phases, but it might be practical, and preferable, at times of low traffic. Signals and markings which only apply at some times could, however, be confusing.
  • The installation addresses only bicycle traffic entering the intersection from New Hampshire Avenue. Traffic control remains as it was for 16th street and U street. Considering the many ways in which bicycle travel could be made slower and/or more hazardous in the name of making it better, this may be a case of “best leave well enough alone,”  but on the other hand, real improvements might be possible.
  • The bike boxes on 16th street could be interpreted as encouraging bicyclists on that street to overtake motorists on the right, then swerve in front of them, as is the more conventional with bike boxes.
  • Just outside the lower left of the picture on New Hampshire Avenue, there is wrong-way parallel parking next to the bike lane. Motorists exiting wrong-way parking spaces are in head-on conflict with bicyclists, but cannot see them if another vehicle is parked ahead. (See illustrated description of wrong-way parallel parking elsewhere, if the explanation here is unclear.) At the top right, on the other hand, note that the bike lane is farther from the curb: this segment of New Hampshire Avenue has back-in right-angle parking, avoiding the sight-line problem.
  • And, while we’re at it, I have another issue with the street grid, though it’s common to many other cities and not readily subject to correction. Streets that go east and west guarantee that twice per year,  for several days, the Sun will rise and set directly along the streets, glaring into drivers’ eyes.  If the street grid ran northeast to southwest and northwest to southeast, this would never happen. All you Pierre L’Enfants of today designing new cities, please take notice, here’s your chance to acquire a reputation as Pierre L’Enfant Terrible!

This installation is the subject of experimentation sanctioned by the U.S. Federal Highway Administration, with observation, data recording and analysis to see how it works in practice. The experimentation may turn up more issues, or reveal that some are of little importance.

Now, dear readers, you also may also have points to add to the discussion. Let the comments fly.

See also: GreaterGreaterWashington blog entry about this installation; Washington, DC Department of Transportation page about it; Google maps satellite view.

James Mackay on bike box implementations

James Mackay describes his experimentation with timing of special signals for bicyclists at an NCUTCD Bicycle Technical Committee meeting.

James Mackay is a practicing traffic engineer who participated in a summer 2009 scan tour of European bicycle facilities. He is a member of the National Committee on Uniform Traffic Control Devices Bicycle Technical Committee (NCUTCD BTC). His comments on European vs. US bike box implementations are published here with his permission:

Bicycle advance stop line implementations I saw in Europe amounted to a five-legged stool, with resultant stability and functionality.

I get very concerned with American implementations that amount to a two-legged stool.

Proposals I see over here lack the individual contribution and resultant system stability of the sum of following five factors which provides a functional system over there:

  1. Near-side-only signals, which greatly reduced motorist encroachment on bike boxes and pedestrian crosswalks;
  2. Traffic signals that provide an advance red/yellow phase indicating that a green indication is imminent;
  3. Trixi mirrors (convex, internally heated mirrors placed on the near side signal pole, directly beneath the motorist’s traffic signal);
  4. Right Turn on Red “RTOR” -or the UK equivalent of LTOR – does not exist in these countries (serving to preclude operational conflicts), and;
  5. Cell phones are not to be used while driving.

Overall the bike boxes were used in cultures with much higher numbers of bicyclists. A motorist in the countries we visited would be much more likely to see a bicyclist using a bike box. This would specifically include truck drivers.

I don’t recall seeing traffic enforcement in the scan tour countries. Seemingly, there was a much stronger social contract in effect. In particular, bicyclist compliance with signals and other traffic control devices was much higher than what we are used to seeing in the U.S.

James Mackay, P.E.

Secretary (Emeritus as of January, 2011), Bicycle Technical Committee, NCUTCD

Also see a description of James Mackay’s bicycle signal experiment.

Comparing crosswalk and bike box

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Bike box rationales

On another Web page, I have discussed the features and operational characteristics of so-called “bike boxes”, in which bicyclists wait for traffic signals ahead of the stop line for motor traffic. I recommend that page as background information for this discussion.

In this posting, I will discuss rationales advanced for the installation of bike boxes.

There are two principal rationales for a bike box, one of which I regard as valid but which might better be served by a different implementation. The other rationale, I find very distressing.

The first rationale is to accommodate a high volume of bicycle traffic, where bicyclists might have to wait through multiple signal cycles behind motor traffic, or else might filter forward and then not have room to wait. I recommend that bicyclists wait behind the first motor vehicle, so as not to be caught on the light change, and to negotiate with the driver of the second vehicle in line. That places the bicyclist in the exhaust of the first vehicle, but that’s better than risking a right hook collision. The exhaust problem has become far less serious in countries which have mandated pollution control on motor vehicles. But — there’s only so much room behind the first vehicle for a couple of bicyclists. A bike box behind the first vehicle would formalize that option, but unfortunately, the length of vehicles varies.

A bike box is advantageous in terms of bicyclists’ travel time when going straight through the intersection, if it facilitates filtering forward past stopped traffic — though, on the other hand, it increases motorists’ travel time. The bike box makes no significant difference in a bicyclist’s through travel time when the bicyclist arrives on the green.

But a bicyclist can get caught at the right side of the roadway when approaching the bike box, and the light turns green. Merging into the flow to go straight, or make a vehicular left-turn, is more advantageous unless traffic is very congested. (And that’s one reason among others that use of a bike lane should not be mandatory!)

The other rationale for a bike box is to encourage more people to ride bicycles by increasing comfort. I find this rationale very scary when the supposedly comfortable facility includes a deathtrap. I call this the “Pied Piper” approach to bicycle planning. It involves some convoluted thinking — bicyclists fear motorists, so, build facilities which appear less scary to the bicyclists.

A bike box with a pre-green signal interval (red and yellow in European practice) provides a warning for a bicyclist not to overtake and swerve in front of the first motor vehicle waiting at the intersection as the light turns green. He/she can still get stuck waiting for through traffic to clear, and the signal to turn red, then green again, if the intention using the bike box was to prepare a left turn (as with a Vancouver, BC bike box and some in New York City) or to cross to the other side of a one-way street (as with a bike box in Eugene, Oregon).

Motorists waiting behind a bike box without the pre-green are expected to look for bicyclists in their right rear-view mirror while also scanning the intersection ahead. That increases the likelihood of mistakes in both tasks, but also, the right rear-view mirror doesn’t provide complete coverage of the area where a bicyclist may be, particularly for the driver of a truck or bus with a high cab and a hood. If the motorist doesn’t look into the mirror at the right time, the bicyclist may have passed outside the field of view seen in the mirror. That is the rationale for additional mirrors, beepers, bicyclist-presence actuated flashers etc. that have been proposed to warn motorists of bicyclists overtaking on the right, and warn bicyclists of motorists preparing to turn right — none of which measures have been implemented in practice and all of which are technological solutions, with the attendant problems of implementation rollout and reliability.

So: what to recommend? here’s what I suggest. Never overtake a long truck or bus with less than 5 feet of clearance to its side, not even in a bike lane. Preferably, overtake on the left or move forward in line with other traffic, but in a traffic jam, you may filter forward *slowly* in a bike lane. Be aware of thehazard of car doors opening from either side, pedestrians stepping out form in front of tall vehicles, etc. Never swerve across in front of a vehicle unless you can be entirely sure that it will not start to move. Make eye contact with the driver, signal your intentions. If you can’t see the driver in a high-cab vehicle, just don’t swerve left. Pulling into line behind a vehicle that is waiting for a traffic signal or stop sign is reasonably safe if you obey these precautions. Swerving across in front of a vehicle waiting first in line, even with a bike box, is only safe if you can be sure that the traffic signal is not about to change.

Alternatives to the bike box?, For less-skillful bicyclists in urban areas, I favor the bicycle boulevard concept, in which bicyclists and motorists share a roadway according to the normal vehicular rules of the road, on a street with low traffic volume — typically, a residential street paralleling an arterial, using diverters and small traffic circles to keep down the volume and speed of motor traffic. This approach avoids the problems with attempting to accommodate conflicting movements with special facilities on a street that also carries heavy motor traffic. There are tradeoffs, to be sure: the bicycle boulevard isn’t a main street, so it may not provide such a direct route between as many trip endpoints — and unless bicycle transportation is taken very seriously, the bicycle boulevard may not have as favorable signalization as a main street. I have seen and ridden bicycle boulevards in Berkeley and Eugene, and they do seem to work rather well in those cities. No, I don’t have use or crash data, only my personal observation.