Tag Archives: MUTCD

Is the NACTO Guide a Design Manual?

In cities around the USA, politicians, under pressure from populist bicycling advocates, have pointed to the NACTO (National Association of City Transportation Officials) Urban Street Design Guide and directed their engineering staff to install treatments which it describes.

I’ll say right here that some of the treatments which the NACTO guide describes deserve attention and inclusion in national design standards — though their presentation in the NACTO Guide typically is flawed, inconsistent and incomplete. Why some deserving treatments are not included in the national design standards is a story for another time.

Other NACTO treatments are so troublesome that they are not widely applicable.

Engineers unfamiliar with bicycling issues may take NACTO designs at face value; other engineers may throw up their hands and comply, faced with the threat of losing their employment. Several engineers who have extensive background and expertise in design for bicycling have resigned, been fired or been demoted when they would not accept the NACTO designs.

What leads to these problems? To put it simply, the NACTO guide isn’t a design manual. It is a smorgasbord of design treatments formatted — right down to digitally-generated loose-leaf binder holes on what are, after all, Web pages — to look like a design manual to politicians and the general public. Bicycle manufacturers funded it to promote street designs which they expect will lead to greater bicycle sales. It lacks the vetting necessary for consistency and accuracy. Its purpose is to generate political pressure to apply the treatments it describes. It is weak on specifics: rife with errors, and with omissions even in describing the treatments it covers.

If I described all of my specific  concerns with the NACTO Guide, I’d be writing a book, so for now let’s just look at a two-page spread of the NACTO Guide, the pages about two-stage turn queuing boxes (2STQBs, for short).

Maybe by now you are inclined to think of me  as a naysayer, so, let me get down to some specifics to dispel that impression. I have had information about two-stage turn queuing boxes online for years, I think that they are a useful treatment, and I use two-stage turns: when I realize that I have reached the street where I need to turn left, but hadn’t merged to turn; when traffic is heavy and fast and I haven’t found an opportunity to merge; when ordinary left turns are prohibited. My favorite example is the left turn from Commonwealth Avenue onto the Boston University Bridge in Boston, Massachusetts, where a no-left-turn sign is posted: motorists have to go around a large loop.

Ok, now let’s consider the spread from the NACTO guide, below.

NACTO pages about two-stage turn box

NACTO pages about two-stage turn queuing box

I have placed that spread online as a PDF file, zoomable to any size you might like. You may click on the link or the image above to get a larger view while reading this text. The PDF will open in a separate browser window or tab. I’ve also posted parts of the NACTO pages in connection with the text below.

Issues of organization and use of technical language

The NACTO treatment of the two-stage turn queuing box presents issues of organization and of use of technical language.

Problems start with the title of the section. A proper title is not “Design Guidance”, otherwise, every section would be named “Design Guidance”. A proper title is the name of the device, here “Two-Stage Turn Queuing Box”. [And not “Queue” but” Queuing.”]

In a proper design manual, the terms “shall”, “should”, “guidance” and “option” go from strong to weak. “Shall” is imperative: for example, a stop sign shall be octagonal. Should, guidance and option statements are increasingly weaker, leaving more room for engineering judgment.

The terms “Required Features” and “Recommended Features” correspond roughly to “shall and “should” but do not have the explicit, legally-defined meanings of “shall” and “should”.

None of the drawings on the two pages are dimensioned, and no dimensions are given in the text. That is to say, these are not engineering drawings, they are only conceptual drawings. How big are the turn boxes supposed to be? Who knows? The width of travel lanes differs from one drawing to the next, but no explanation is given for that. When politicians start beating on the door for NACTO treatments, standards-setting bodies and traffic engineers have to try to fill in the missing information. For specific projects, that task often is passed along to hired consultants who make their living by promoting and designing special bicycle facilities. Yes, there is a conflict of interest.

Specific comments

Now, either click on the image of each section of the page below to open it in a separate browser tab, or zoom the PDF to at least 50% size so you can read the text in connection with my specific comments .(You may open it now if you didn’t already.)

Comments on the left-hand page

The left-hand page includes text which may look like design specifications, and drawings which may look like design drawings — to a layperson.

Left half of left-hand page

twostageturn_guidanceLL

Point 1: “An area shall be designated to hold queuing bicyclists and formalize two-stage turn maneuvers.” This is under the heading “Required Features.”  A 2STQB is only one way to turn left among others, an option, subject to engineering judgment or specific design warrants. There is neither the room nor the need for a 2STQB at most intersections. Lacking here is any statement as to where a 2STQB is appropriate, but the “shall” statement here is inappropriate: appropriate shall statements would describe what features are required if a 2STQB is installed. As of May 2014, the 2STQB is still in experimental status with the Federal Highway Administration — as are all details of its design, and so no “shall” statement at all is appropriate.

A proper design manual would include guidance about speed and volume of traffic; the additional delay usually required for a two-stage turn; whether bicyclists might take an alternate route entirely; whether use of the box is  mandatory, placing bicyclists who make other types of turns in violation of the law.

Point 4: “In cities that permit right turns on red, a no-turn-on-red sign shall be installed.”

According to the wording here, if the installation is not in a city, the sign is not required.

But also, the shall statement is overly broad, and incomplete. The sign is needed only if right-turning traffic would be in conflict with the bicyclists waiting in the 2STQB: unnecessary in the cross street if traffic turns right before reaching the box or cannot turn right, and unnecessary on the entry street if the cross street is one-way right-to-left. Does the sign belong on the entry street or the cross street, or both? That is not stated. Details, details…

Point 6: The comma makes nonsense of this sentence. Where is the box to be positioned?

The other, subsidiary “should” and “may” statements on this page also are contingent on official approval of the underlying design, and are lacking in detail.

Right half of left-hand page

twostageturn_guidanceLR

Something really leaps out at me here: take a look and see whether it leaps out at you too.

OK, ready? Three of the six illustrations show a line of travel (in blue) for bicyclists straight across an intersection and then illegally and hazardously turning right, directly into the face of approaching traffic in a cross street.

In showing this bizarre routing, the NACTO Guide also fails to address issues with the actual route which bicyclists might take.

Five of the six illustrations show that bicyclists would somehow turn 180 degrees in place. That requires dismounting and is slow and awkward. How would a bicyclist turn when the traffic light is about to change? When other bicyclists are already in the box? What about tandems? Bicycles pulling trailers? Bicycles carrying heavy baggage?

The drawings show a subtly implied but selectively addressed-threat: lanes where motorists travel are shown in a threatening shade of pink — whoops: except in the cross street where bicyclists ride head-on at motorists.

Four of the six illustrations show motor vehicles in right-hook conflict with bicyclists headed for the queuing box. The motor vehicles are turning out of the threatening pink area into what is portrayed as the safe zone– the right-hook zone. In two of the pictures,  vehicles have already impinged on the blue line which represents the path of bicyclists crossing the intersection. Green paint, which has become a catch-all warning of traffic conflicts in bicycle facilities, is shown in the queuing box, it is not shown in the conflict zone. (By way of comparison, Dutch practice in such conflict situations is that the motorist must always yield, and to use “shark teeth” markings to indicate a yield line.)

Two of the drawings show bike lanes in the door zone of parked cars.

The middle left illustration shows a receiving bike lane at the top, out of line with dashed markings in the intersection, so bicyclists bear right just before they cross a crosswalk, potentially colliding with pedestrians who would expect them to continue straight.

All of the illustrations show two-stage turns across two-lane one-way streets, though the two-stage turn queuing box is most useful where a conventional left turn is illegal, unusually difficult or hazardous — for example, when turning from a major, wide arterial street with heavy traffic, or one with trolley tracks in the median.

As already indicated, none of the drawings are dimensioned and no dimensions are given in the text.

Comments on the right-hand page

The right-hand page gives annotated pictures of conceptual installations, with angled views from overhead.

Left half of right-hand page

twostageturn_guidanceRL

The street going from bottom to top in the picture is one-way, as can be inferred by the direction in which vehicles are traveling. That the cross street is two-way may be inferred from the locations of traffic signals and the existence of the queuing box. A real design manual would be explicit about how a treatment would apply, depending on the directions of traffic in the streets.

The end of the traffic island next to the queuing box protrudes so far and is so sharply as to make right turns awkward. No explanation or guidance is given on this issue.

Traffic signals are shown for motor traffic on both streets, but no traffic signal is shown facing the separate bikeway in the street!

Point 3: “Shall” — mandatory — wording differs from that in the same point as made on the opposite page. A real design manual would have a single, consistent statement. “Queue box shall be placed in a protected area.” The queuing box shown here is not protected from right-turning traffic in the cross street. How would that right-turning traffic be managed, or is it permitted at all? Such issues are addressed in a real design manual.

Point 6: “Optional queue box location in line with cross traffic.” The preferred queuing box, then, is not in line with cross traffic. On getting a green light, bicyclists in the queuing box would have to merge left inside the intersection unless there is a receiving bike lane after the intersection, but none is shown. Merging inside an intersection results in hazardous conflicts and is generally illegal. What warrants the choice of one or the other option? It isn’t stated.

Point 8: The illustration shows motorists and a bicyclist inside the intersection, and so they must have a concurrent green light — or, they would if any signal were shown facing the bikeway. Markings guide bicyclists across the intersection, but also into the path of right-turning traffic. The bicyclist and the motorist in the right-hand lane at the bottom of the picture are on a collision course if the motorist turns right.

What is the meaning of the curved markings adjacent to the bicycle parking in the middle of the street? Does the lane with bicycle parking start as a lane with car parking, additionally hiding bicyclists from turning motorists? Or is this an additional lane for motor traffic, discontinued at the intersection, precisely where more lanes are needed to store waiting traffic? Not shown.

Right half of right-hand page

twostageturn_guidanceRR

There is a right-hook threat at both bike lane entries to the intersection.

Bicyclists headed from bottom to top in the bike lane are riding in the door zone of parked cars, and closer to the cars after crossing the intersection.

Point 9: As in the left half of the page, placing the queuing box to the right of the travel lane when there is no receiving lane ahead assures that motorists will overtake bicyclists in the intersection and that bicyclists will have to wait for motor traffic to clear before they can proceed. Motorists waiting to turn right will be stuck behind the bicyclists. Placement out of line with motor traffic is described as the option here, rather than as the preferred treatment as on the left side of the page, and the problem is acknowledged in the caption to this drawing, though no explanation for the different choices is given.

Point 10: A jughandle may be useful if traffic is so heavy or fast that bicyclists have difficulty merging to the normal left-turn position near the center of the street, but then traffic is also so heavy and fast that a signal is usually necessary, not merely to be considered — unless there is already one upstream.

Point 11: Yes, signage may be used, but what signage? A real design manual would show the signs and where they are to be placed.

Point 12: A bicycle signal might be installed, but where? for the entry? For the exit? Its timing?

Point 13: Guide lines, pavement symbols and/or colored pavement. Which? Where? Why?

Had enough?

When the marketing department plays traffic engineer

The photo shows “Cycle Lane” raised barriers, from the company Traffic Logix, on Long Island, New York, USA.

Traffic Logix Cycle Lane raised barrier

Traffic Logix Cycle Lane raised barrier

Here’s a quote from a page on the company’s Web site promoting  the barriers.

CycleLane is a smart, safe solution that provides a visual separation between vehicle and bicycle lanes. It ensures clear separation of traffic, with a unique sloped profile to prevent vehicles from entering the bike lane. The side adjacent to the vehicle lane has a high profile while the side parallel to the bike lane has a lower profile to divert bicyclists away from traffic and back into the bike lane.

Whoever wrote this evidently is not familiar with the physical concepts of center of mass or coefficient of friction. This device is a tripping hazard. A bicyclist who strays into it will not divert away from traffic, but instead will topple over into the next lane. There also is the possibility of a stopping-type incident with over-the-handlebars ejection when a bicyclist’s front wheel strikes the end of one of these barriers.

The barriers also are shown so tightly spaced that a bicyclist cannot merge into or out of the bike lane.

For these reasons, the US Manual on Uniform Traffic Control Devices, section 9C.02 says the following:

10 Posts or raised pavement markers should not be used to separate bicycle lanes from adjacent travel lanes.

Support:

11 Using raised devices creates a collision potential for bicyclists by placing fixed objects immediately adjacent to the travel path of the bicyclist. In addition, raised devices can prevent vehicles turning right from merging with the bicycle lane, which is the preferred method for making the right turn. Raised devices used to define a bicycle lane can also cause problems in cleaning and maintaining the bicycle lane.

The product is almost beyond belief; its design leaves the manufacturer wide open to liability lawsuits when bicyclists are injured or killed. The promotion could place frosting on that ugly cake, with claims of false advertising.

Still, this is only the most extreme example I’ve seen of ill-conceived, or at best, untested and unproven, marketing-driven purported safety measures targeted toward bicyclists. Some, like this one, are products, but others are design treatments which create the perception of safety without necessarily increasing actual safety.

Enough.

What color is your bike lane?

Should the pavement in a crosswalk, or special on-street bicycle facility, be painted a special color? Under what conditions? What color?

European countries use color. Let’s look at a few examples and see what they might teach us.

First let me say that my showing treatments here does not mean I endorse them. In the first couple of examples below, running a bike lane around the outside of a roundabout defeats the purpose of the roundabout in maintaining smooth traffic flow. Having cyclists and motorists merge into a single, slow flow of traffic has been shown safer for the cyclists too.

That said, this pink bike lane is in Thisted, Denmark — photo taken in 2006.

Roundabout with pink bike lane, Thisted, Denmark. Photo by Dan Carrigan

Roundabout with pink bike lane, Thisted, Denmark. Photo by Gordon Renkes.

This sea-blue bike lane in another roundabout is in Lyngby, Denmark.

Roundabout, Lyngby, Denmark, with blue-painted bike lane. Photo by Ryan Snyder from 2011 Association of Bicycle and Pedestrian Professionals calendar

Roundabout, Lyngby, Denmark, with blue-painted bike lane. Photo by Ryan Snyder from 2011 Association of Bicycle and Pedestrian Professionals calendar.

These bright blue-green lanes are in Copenhagen, Denmark.

Blue-green bike lanes in Copenhagen. Photo by Jon Kaplan

Blue-green bike lanes in Copenhagen. Photo by Jon Kaplan

This red bike lane is in Winterthur, Switzerland.

Bike lane in conflict zone, Winterthur, Switzerland. Photo by James Mackay

Bike lane in conflict zone, Winterthur, Switzerland. Photo by James Mackay

As these photos show, there is no consistent color for carpet painting of bike lanes in Europe. German-speaking countries do appear to have settled on red, but Denmark has used at least three different colors in recent years.

There are issues with the effectiveness of color too.  A couple of years ago, the US Federal Government sponsored a scan tour so traffic engineers and planners from around the country could examine bicycle and pedestrian facilities in Europe. According to one participant in the scan tour, Denmark uses paint only on one or two bicycle routes through an intersection, having found that using it on more routes negates any benefit. Clearly, it is important to address such issues.

What message does the color convey? A common use is to indicate conflict zones — where motorists must expect bicyclists and yield to them. At other times, color is used where no such conflict exists. Here is an example from Bristol, in England where the message is  probably “no cars here”:

Barrier-separated bikeway with colored pavement, Bristol, England. Photo by James Mackay

Barrier-separated bikeway with colored pavement, Bristol, England. Photo by James Mackay

Also according to the scan-tour participant, Switzerland uses red only where there is a history of crashes — leading to inconsistency in the message because crashes happen for different reasons. In the following example, colored pavement indicates a place of refuge from motor traffic — quite the opposite of the conflict zone in the previous Swiss example.

Who is the message of colored pavement supposed to be for? Bicyclists? Motorists? Both? Here it is apparently only for bicyclists.

Swiss use of colored pavement in non-conflict zone. Photo by Nicklaus Schranz.

Now let’s look at some US examples. The first common bike-lane color in the USA was blue, as used in Portland, Oregon. This bike lane in Cambridge, Massachusetts followed Portland’s example:

Cambridge, Massachusetts blue lane

Cambridge, Massachusetts blue lane

Blue led to objections, because it already had a designated use in the US vocabulary of colors: handicapped parking spaces.

Green was proposed instead, and it is on the way to become a standard. Unlike blue, it shows up under the monochromatic yellow-orange of sodium-vapor streetlamps as well as the blue-green of mercury-vapor lamps. Green markings are the subject of several experiments testing their use under various conditions.

Green bike lane in Seattle, Washington

Green bike lane in Seattle, Washington

Yes, experiments. To be included in the national reference, the Manual on Uniform Traffic Control Devices, and to be approved for general use, a new treatment has to be tested to see whether it affects behavior in an intended and desirable way. This is reasonable in the light of safety issues and expense. Where does it make sense to use paint; what consistent and understandable message might the paint send? What about durability of the paint; should it be reflectorized…there’s a tradeoff: reflectorized paint is slipperier. And so on.

Any state, city or town may install a nonstandard treatment and is exempted from legal liability if it works with the Federal Government and the National Committee on Uniform Traffic Control Devices, collects data and prepares a report on how the treatment worked.

Some communities don’t bother. Madison, Wisconsin has installed this crimson bike box. Crimson, even more than the European red, looks nearly black under both types of streetlights.

Red-painted bike box in Madison, Wisconsin. Madison Star-Intelligencer photo.

Crimson bike box in Madison, Wisconsin. Craig Schreiner/Wisconsin State Journal photo.

Madison, Wisconsin, of all places — a city with a long-standing and most knowledgeable bicycle program staff — one of the best in the nation. A city which has in the past known how to be innovative in ways that really work — see this example — and how to avoid costly and deadly mistakes.

Why the crimson bike box, then?

For many American bicycling advocates, trips to Europe take on the aura of a religious pilgrimage. Anything in Europe has to be better than what we do here, even if it isn’t.

As an aside: this reminds me of the American inferiority complex about European painting and music around the year 1900. American composers and artists who imitated European styles are largely forgotten today. We remember the American originals, who, certainly, adopted much from European styles, but who found their own voice. Scott Joplin. Charles Ives. George Gershwin. Duke Ellington. Aaron Copland. Bessie Smith, Billie Holliday, Ella Fitzgerald, Andy Warhol, Georgia O’Keeffe… but I digress.

It’s more than a question of an inferiority complex. It’s also about corporate lobbying. Bikes Belong, the bicycle industry’s political lobby, organizes its own scan tours. The goal of this lobby is to increase sales of bicycles — and why bother with troublesome, boring, nerdy details. Instead of sending professional program staff, Bikes Belong sends politicians. This is from the Bikes Belong Web site:

Zach [Vanderkooy] leads our project to make U.S. bicycling safer and more appealing by helping cities adapt the world’s best bike facility designs, policies, and programs inspired by leading bicycling cities in Europe.

And this is from a story on the Madison.com news blog:

The bike boxes are the first project from a European fact-finding tour of bicycle-friendly cities in Germany and the Netherlands that Madison Mayor Dave Cieslewicz, Dane County Executive Kathleen Falk and 19 other civic and business [leaders] made last month.

If you work for the bicycle program staff of a city, the Mayor is your boss, and you do what the Mayor tells you to do, or you can very well lose your job.

I wrote that before I learned of the following:

Arthur Ross, Madison’s long-time, nationally-recognized bicycle and pedestrian program manager, is being demoted — see this story.  Whether it has to do directly with the crimson bike box or not, I don’t know yet.

I’ve said it before: in planning for bicycling, we need to do better than the Europeans. Certainly so on the issue of painted pavement, because, clearly, Europe doesn’t use it in any consistent or logical way. We need to do better with other, similar issues too, and because we face bigger and different challenges — and because it would be very unfortunate to lose the opportunity to do better.

In its turn, Europe may learn from us too.

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.

Idaho special bicycle laws

Idaho law allows cyclists to treat a stop sign as a yield sign. See http://www3.state.id.us/cgi-bin/newidst?sctid=490070020.K
It also allows a bicyclist to treat a traffic signal as a stop sign.

I would support the traffic signal aspect of this law as a second-rank stopgap for the installation of signal actuators that detect bicycles and that are smart enough to adjust the signal timing to the speed capability of the vehicle.

Today’s electromagnetic loop detectors can detect bicycles if properly designed and installed, but many jurisdictions are still installing ones that cannot, or installing them incorrectly. (For example, even Portland, Oregon installs bicycle-sensitive detector loops only in the bike lane, and so a bicyclist preparing a vehicular left turn, or overtaking traffic on the left, will not be able to trip the signal). Bicycling advocates should promote best practices in application of loop detectors, the most common detector technology.

But detector technology is improving, with video. ultrasonic and infrared detectors becoming able, at least in theory, to distinguish a bicycle from a motor vehicle. Bicycling advocates should promote continued research, development and application of improved signal detection technologies through professional organizations and through the National Committee for Uniform Traffic Control Devices.

All this said, there will still be intersections where the technology is not up to date, or where the detector is malfunctioning, or where fixed-interval signals produce a long red even though there is no cross traffic. I think that it is reasonable for bicyclists to be permitted to proceed cautiously on the red under such conditions. This special permission could, however, get out of control — on the one hand, with the engineering profession abdicating its responsibility to provide signals that work, and on the other hand with bicyclists abusing the rule and crossing at times when other traffic has to yield to them.

As to the stop sign provision: the most important message of the stop sign is to yield to cross traffic. Usually, a yield sign would be sufficient. Almost nobody, bicyclist or motorist, comes to a complete stop for a stop sign unless there is cross traffic to which to yield, or a short sight distance that requires a stop. Stop signs are heavily overused in this country, but unfortunately, stop signs are the first thing the public thinks of in order to increase traffic safety. For my comments on how this contrasts with European practice, please see this other posting.

Also, bicyclists don’t have a car hood in front of them and are able to see the intersection before pulling out into it, so a stop is needed less often. And bicyclists can restart faster and get across a smaller gap without stopping and putting a foot down. So I offer warmer support to the Idaho stop sign provision.