Tag Archives: Manhattan

Manufacturing traffic jams on Grand Street, Manhattan

Someone has watched my video of Grand Street, in Manhattan, and commented:

John, I watched the Grand Street video (which was kind of fun) but I couldn’t help but notice you are passing a lot of cars, which makes your average speed seem reasonable for the environment.

That average speed, including waits for traffic lights, was 5.5 miles per hour, half my usual. Yes, I do wait for the lights, though many New York bicyclists aren’t so patient.

Please have a look at the video so you can evaluate the rest of this post. Note especially the bus stopped in the street near the start of the video, because that will play in my comments.

Why were my riding companion John Schubert and I passing a lot of cars — and not only parked cars? The others were stopped cars. Even at 5.5 mph, you can pass stopped cars.

Grand Street is one block north of a major arterial, Canal Street, and carries overflow traffic arriving from New Jersey via the Holland Tunnel. In case you want more detail, I’ve posted photo gallery with maps online. I thank John Ciccarelli, John Schubert and Steve Faust, my companions in exploring Grand Street, for the commentary and photos which they contributed.

Here’s one photo, as an example — and you may click on it to see it in the photo gallery. That’s Steve Faust, in the yellow parka.

Trucks blocking the Grand Street bikeway

Trucks blocking the Grand Street bikeway

Grand Street passes through Manhattan’s Chinatown — accounting for the street vendors standing and walking in the bikeway near the end of the video. Grand Street also is where the infamous Chinatown intercity buses pick up and discharge passengers, to avoid paying to use the Port Authority terminal uptown.

Grand Street now has only one travel lane. A second lane was removed to create the bikeway. Whenever a bus stops — or any other vehicle stops in the travel lane — all other traffic stops and waits behind it. Traffic backs up for several blocks.

The bus drivers park the buses diagonally to prevent motorists from sneaking past and colliding with bus passengers, though this does not prevent bicyclists from sneaking past and colliding with bus passengers. You can see one of the buses parked diagonally near the start of my video.

The traffic backups, then, illustrate the law of unintended consequences. The backups result from the redesign that created the bikeway. Possibly, the designers thought that they would calm traffic by reducing Grand Street from two travel lanes to one, in the hope that the traffic from New Jersey would go elsewhere. It didn’t work. To calm traffic, you have to reduce the actual traffic, rather than to try to cram the same traffic onto a street which can’t accommodate it. Instead of calming traffic, the designers created traffic jams, increasing fuel consumption and air pollution.

My observation about traffic flow before the redesign is confirmed by an early, prototypical pre-Streetfilms video. The video stars Mark Gorton, the money man behind Streetfilms, and shows conditions on Grand Street before the redesign. Motor traffic flowed smoothly. Gorton shows vehicles stopped to load and unload, but they don’t block the street, with a second lane available for overtaking.

Gorton’s main concern is with width of the sidewalks, a valid concern in my opinion, though the sidewalks are in fact only narrow in some blocks, and Gorton takes his advocacy to the opposite extreme. He shows a Photoshopped example of how we need to “return control of the street to the communities that live here and the people that live here” by converting part of the roadway into an open-air restaurant — placing restaurant patrons elbow-to-rear-view mirror with moving motor vehicles, where the diners can enjoy a fine mix of food aromas and exhaust stench. This treatment reflects the influence of the “shared space” designs of British architect Benjamin Hamilton-Baillie. These treatments turn the entire street into pedestrian space, and tame motorists, because they can now safely travel only at pedestrian speed without killing pedestrians.

Tellingly, Mr. Gorton never mentions bicycling. Evidently, he had not yet discovered it.

“Return to the people” is code language for “take away space from motorized uses.” That is, to take control away from people who use motor vehicles and give it to “the people,” who all agree perfectly with the point of view expressed in the video. If that sounds vaguely Leninist to you, well, yes, I think so too. Ah, New York, where a wealthy hedge fund manager sounds off with Leninist rhetoric!

Real-world, American-style political pressures came to bear, and we now see the outcome. It’s rather clear that the community, some community — some people — residents, or business people, probably both, and for better or worse — wanted parking for motor vehicles, because there’s still nearly as much as before. On the other hand, Grand Street now has restricted loading zones — and not enough to meet demand. The business community either didn’t understand what would happen, or had too little political clout to demand more space.

Part of the street’s width was, however, “returned to the people” as a bikeway which is, in reality, a sidewalk extension, an outcome so predictable that I would have to laugh if the street hadn’t become such a traffic tangle, and if I weren’t required by law to ride on that sidewalk extension.

Bicyclists didn’t come out very well in this political exercise, and neither did motorists. Pedestrians came out best. They got their wider sidewalk, even if it is supposed to be a bikeway.

OK, now I’ve complained, so it’s my duty to offer a positive alternative.

Are you expecting a screed now on the joys of bicycling in Manhattan traffic on streets without any special treatment for bicyclists? Sorry to disappoint you, I’m not going to claim that Grand Street was a great street to ride on before the bikeway was constructed.

In my opinion, the Grand Street design is not thoroughgoing enough — not radical enough in one sense and not conservative enough in another. To make the street safe and attractive to bicyclists, including younger and less skillful ones, it would be necessary to displace through motor traffic to another street, and to get bicyclists out of the pedestrian zone. A way to accomplish that would be to traffic-calm Grand Street (or maybe another nearby parallel street) using barriers and diverters, more or less like the ones in Berkeley, California — so the street carries only light, local traffic.

In other words, transform the street into a neighborhood street, whose main purpose is local transportation at neighborhood-friendly speeds, like the bicycle boulevards in Berkeley — not a segregated mess, and not a pedestrian playground like upper Broadway in Manhattan. Many crosstown streets in Manhattan look promising for the treatment I propose, and are quite easy to ride now, even without intentional traffic calming.

If the volume of motor traffic were much lower, we might also consider widening the sidewalks where needed.

You may notice my heresy, from the point of view of segregationist bicycling advocates: some motor traffic must remain, as on the Berkeley streets, so the entire street doesn’t become a shared-space ped zone where pedestrians walk with abandon, and bicyclists have to play dodg’em.

John Schubert and I shot another video on Grand Street the same day. At the end of the video, you may view how motorists harassed us on a section without the bikeway, but while on the part with the bikeway, we waited over a minute for a Chinatown bus to unload, had to ride very slowly at one point behind a man with a food vending cart, and had to ride in the travel lane for several blocks where the bikeway was obstructed.

You might also have a look at this video by a unicyclist. It’s a bit shaky, but he comes to the same conclusions I do.

Green Wave, Checkered Flag?

A green wave moves out, Manhattan, 1986.

I am writing this post in response to comments by Mighk Wilson and Khalil Spencer on another post on this blog. They discussed the difficulty of cycling in a city with synchronized traffic signals (a “green wave”) set to a higher speed than cyclists can manage, and the potential of a slower green wave to make a street more attractive for cycling. I’d like to take a more general  look at the green wave and how it affects traffic.

My understanding of the green wave is based mostly on experience. (And so, anyone who can provide more details based on theory, or can correct me, please do…)

In my high-school years, I lived and learned to drive in Baltimore, Maryland, USA, one of the first cities to implement traffic signal synchronization. I have also lived, driven and cycled in Manhattan, where most traffic lights are timed to create green waves.

A green wave can only work under a limited set of conditions. If these do not apply, then despite best efforts to time traffic lights for the smoothest possible traffic flow, a signal sequence can still appear random. Drivers have no clear strategy for avoiding red lights beyond speeding up when the next light is still green. On the other hand, when a green wave is working smoothly, drivers may feel as if a green-wave Tinkerbelle is darting along overhead and pointing her magic wand at every traffic light to turn it green.

Traffic engineers use clever math so a green wave, surprisingly, can be applied to streets heading in more than one direction the same time — though it words better if they are one-way. Heading north on Charles Street from church in downtown Baltimore, my family would get  green lights for block after block, except at the few two-way streets, where all bets were off. Then as we headed into the more random street pattern at the north end of the city, we just had to take each traffic light as it was. On the other hand, traffic lights were less frequent in this less densely built-up area.

My experience was similar in Manhattan. The green wave worked smoothly on one-way streets and avenues, but  when crossing two-way ones, and when driving on them, it didn’t. This obvious difference gives drivers a strong incentive to use one-way streets and avenues for through travel, where possible. Advocates of the sort who would view streets as a neighborhood resource often protest conversions of two-way streets to one-way, see for example this call to action. Traffic engineers who are concerned with the effect on congestion and crash rates have the opposite opinion — see, for example, this presentation. (I expect that the choice is not quite so stark as these two examples make it — as usual, such decisions must be made on a case-by-case basis.)

A green wave works smoothly only when there are no stop signs on a green wave street, though stop signs can be used on cross streets.  Double-parked vehicles, vehicles that have entered the street and are waiting for a light to change, vehicles — including bicycles — that can’t keep up with the pace set by the signals — anything that slows traffic down or reduces the number of lanes available increases the likelihood of not keeping up with the pase set by the lights.

A green wave often encourages travel faster than the pace set by the signals. That’s because there is an advantage in racing to the front of a platoon — where each signal has just changed to green — when preparing a turn — then after turning, racing to the end of the block so as to catch the end of the green there. A driver may speed through another few blocks to get to the front of the platoon before turning again. The advantage of this tactic is quickly obvious: After turning the corner at the head of a green wave onto another green wave street, a driver will be facing a signal at the next intersection which is about to turn yellow, then red.

The typical 30-mile per hour speed limit in grid cities like Manhattan often leads to motorists’ speeds considerably in excess of that limit, and to more unpleasant conditions for bicyclists.

On the other hand, synchronizing signals to a speed more comfortable for bicycling will discourage use of a street for through motor-vehicle travel, making it more attractive for bicycling. I have ridden on a street in Saint Petersburg, Florida, with the signals synchronized to 15 miles per hour, and it achieved that goal quite well. It would have worked better if it had been one-way — it ran up a moderate slope from the waterfront, and for most bicyclists, 15 miles per hour was hard to maintain. Downhill, on the other hand, the speed setting could have been 20 miles per hour without creating difficulties for bicyclists.

Bear in mind, though, that comfortable level-ground travel speeds for bicyclists cover a 3 to 1 range , from about 25 miles per hour down to 8 miles per hour — not nearly as uniform as for motorists, even considering the issues with motorists’ speed already mentioned. A predictable increase in the volume of electrically-assisted bicycles and motor scooters will complicate the issue of speed setting even further. The advantage of a slow green wave, given these issues, is not so much to allow bicyclists to travel farther before facing a red light as to discourage use of the street for through travel by motorists.

Guest posting by John Schubert: New York, City of Confrontation

Responding to an article in the New York Times, a correspondent asked John Schubert

Why isn’t NYC concerned about being sued because of lousy bike-lane-
design-caused wrecks?

and he replied:

Good question. I think it’s important to know the answer from NYC’s point of view. I’m not their spokesman, but I’ll try.

First of all, they get sued no matter what they do. It’s a city of confrontation.

Second, NYC knows it will always have collisions, injuries and deaths. They would not view any one street design as a perfect protection against these problems, nor against litigation.

Third, they are SO bombarded with aggressive drivers, nonmotorized road users wanting some sort of relief from aggressive drivers, and the usual paint and path propaganda, that they buy into the idea that separation is necessary in NYC, even if not elsewhere, because NYC is unique.

I believe NYC does have a civility problem. Separated bicycle facilities don’t solve that problem, but in the minds of true believers, at least they avoid that problem. I think you can’t have a livable community without addressing THAT problem.

NYC does have other unique concerns. I suspect the biggest is the huge volume of midblock car stops, more than anywhere else, mostly because of taxis getting and discharging passengers. I think the designs they use to answer this are silly, but the ‘vehicular cyclist’ alternative hasn’t been made appealing to them. Yet.

Gridlock Sam’s magic powers!

New York’s former Traffic Commissioner and Chief Traffic Engineer, Sam Schwartz, “Gridlock Sam,” who describes himself as a “traffic guru”, has posted a Web page [updated and expanded since my original posting, apparently deleted sometime after October, 2014 but available on the Internet Archive] instructing bicyclists and truckers in how to interact. Truckers are supposed to double-park outside a bike lane, and bicyclists are supposed to ride in the channel between the curb or curb parking and the double-parked trucks.

[Update to post, November 2011: Sam misinterprets the New York ordinance prohibiting double parking in bike lanes as also requiring bicyclists to stay in the bike lane. As this is unsafe, and in some cases impossible, it is not required even under New York City’s restrictive mandatory bike lane ordinance. City ordinances, at least as Sam interprets them, do permit truckers making deliveries to park outside the bike lane, reflecting the assumption that cyclists will run the gauntlet between the parked truck and curb or parked cars. The same apparently applies to taxis discharging passengers.]

The following is an image from Sam’s page. I do not endorse what is shown! Please read on!


Look at that drawing again, carefully. You may click on it to see an enlarged version, if you like.

The bicyclists are giants, and the cars are tiny! The car in the middle, where it poses the worst problem for the bicyclists, is by far the smallest.
Continue reading

Livable Streets proposal lacks credibility

I’m looking at a GOOD magazine/Streetsblog proposal for a “livable street”

This is a prime example of what I call the Photoshop school of traffic engineering. Anyone with computer graphics skills can generate a before-and-after comparison like this. Often, it looks very attractive to the untrained eye — but, whether the proposed changes make sense is another issue entirely.

It would be nice if the Streetsblog people who created this graphic had a few more clues about street design. Some of the issues:

Continue reading

Technical and legal issues with the NYC 9th Avenue bikeway

All intersections along the NYC 9th Avenue bikeway are signalized, and it has separate bicycle signal phases at most of them. At the time of the field trip, December 5 and 6, 2008, some of the signals (especially at the north end) had not yet been installed or were not yet working, and so another visit to the site would be useful to view the complete installation.

Manhattan has typically in the past (since Henry Barnes set it up in the 1960s) had signals on the one-way avenues timed in sequence for 30 mph, except at two-way cross streets where that was not possible.

Continue reading

Guest posting: John Ciccarelli on the NYC Broadway bikeway

[John Ciccarelli is a consultant on bicycling, League of American Bicyclists Cycling Instructor and member of the Bicycle Technical Committee of the National Committee on Uniform Traffic Control Devices. These comments are based on his observations during a field trip to examine bicycle facilities in New York City in December of 2008.]

Broadway bikeway, Manhattan

Broadway bikeway: clogged with pedestrians

For me, the pedestrian conflicts on a new unconventional Manhattan bikeway — on the pedestrian-enhanced blocks of Broadway starting south from Times Square — rendered that bikeway nearly useless — even though those blocks of Broadway are similar to the
9th Avenue layout in several ways:

  • Both streets are multi-lane one-way-southbound
  • Both have a left-curbside one-way bikeway
  • At intersections there is a bike signal and a left-turn pocket and turn-arrow for motor vehicles (where the cross street is two-way or one-way-left) Continue reading

Guest posting: John Ciccarelli on the NYC 9th Avenue bikeway

New York's 9th Avenue bikeway at 29th Street

New York's 9th Avenue Bikeway at 29th Street

Manhattan’s 9th Avenue bikeway, extending from 31st Street to 14th Street, is mostly a signalized left-curbside one-way on-street path, separated over most of its length from mixed-flow travel lanes by an in-street car parking lane. A couple of blocks near the end are separated only by a striped median or a single stripe. The barrier separation is the first of its kind in Manhattan but as is usual with bike lanes on Manhattan’s one-way avenues, the 9th Avenue bikeway on the left side — for two reasons:

a) Buses, which run frequently, use and stop in the rightmost lane of this multi-lane one-way street

b) Truck deliveries and taxi pickups/dropoffs occur in the rightmost lanes

Those activities are impractical on the left side of 9th Avenue on the bikeway blocks because the bikeway is separated from the rest of the Avenue by a left-side in-street parking lane. Continue reading

Review of New York Times article of June 5, 2007

This is a review of the article Cars and Bikes Can Mix, When the Rules of the Road Are Clear, which appeared in the New York Times on June 5, 2007 and is available online.

That’s a good headline, except that the problem is usually with behavior, not the rules of the road. The author is an all-too-typical bicyclist who has not learned or been taught good information, and the article has a number of significant errors. It isn’t up to the Times’s standards.

The article mentions the League of American Bicyclists “Share the Road” campaign but without identifying it. The author would do well to attend a League Bike-Ed class.

The article leads with what bleeds, descriptions of fatal crashes. Fear factor is clearly at work here.

Pictures of crash types show them but not how to avoid them — useless information.

And now, I’ll comment on some specific statements in the article.

  • “Thanks to the proliferation of designated bike paths and the growing use of helmets, deaths among bicyclists have declined to around 600 a year from about 800. Still, 600 is 600 too many, as are the approximately 46,000 annual injuries that cyclists suffer in crashes with motor vehicles.” Bike paths don’t have a significant effect on the fatality rate; most riding is on streets. The 600 to 800 figure is about right for the USA, but the article confusingly makes several references to New York City. Cyclist fatalities per year have declined substantially since the 1970s, but largely due to a decline in cycling by children. There has been a small uptick in cyclist fatalities, along with other traffic fatalities, in the past few years.
  • “Prompted by organizations like Transportation Alternatives, the city has created hundreds of bike paths on or near city streets.” The facilities on streets are bike lanes, not bike paths. Hundreds of miles, I think, not hundreds of facilities. Paths adjacent to city streets, with few exceptions, should not be described as a safety improvement, as they have a poor safety record due to crossing and turning conflicts at intersections.
  • “Bicycles are legally entitled to use most roads, though they must ride on the shoulder when the speed limit exceeds 50 miles per hour.” Bicyclists are required to allow other traffic to overtake when safe in all states, but are required specifically to use the shoulder only in Maryland, Alaska, New York and Colorado. Each of these states has exceptions to the rule, for example to turn left or if the shoulder is not usable. See Paul Schimek’s guide to traffic laws.
  • The author advises motorists: “[w]hen turning right, signal well ahead of time, turn from the middle of the intersection rather than across the bike path, and make sure no bike is on your right before you turn. Do not pass a cyclist if you will be turning right immediately after.” Again, the author confuses bike lanes with bike paths. Her advice for motorists to turn right from the left lane is contrary to law, which requires that motorists merge into the bike lane. “[A]nd make sure no bike is on your right before you turn.” This is a problem when turning right from the left lane — the look to the rear can distract motorists from the traffic situation ahead in the intersection; and the bike lane can give bicyclists a false sense of security in moving forward into motorists’ right rear blindspot. Bicyclists best avoid this by merging left, or not advancing to the head of the bike lane when a vehicle is waiting there.
  •  “More than half of collisions occur when cyclists and drivers are on perpendicular paths,” Poorly stated, inaccurate and misleading. The expression “Perpendicular-path” collision apparently is an invention by the author. Most car-bike crashes occur due to crossing and turning movements — not necessarily perpendicular, for example if a motorist overtakes a bicyclist and turns right. What the author doesn’t say, apparently because she doesn’t understand it, it that only about 7% of car-bike crashes are the widely-feared rear-enders.
  •  “Signal all turns and stops and make full stops at stop signs.” The author gives rote advice which fails to convey the purpose of signaling. Bicyclists need to signal to indicate the desire to merge when preparing a turn, to overtake stopped vehicles and in many other situations. The law in most states exempts bicyclists from signaling when the hands must be on the handlebar for control. There is in any case no need to signal once in the position to turn — the bicyclist’s position makes the intention clear. Bicyclists can’t signal when using handbrakes. But there is generally no need to signal when slowing or stopping, as a following driver can see past the bicyclist, who is usually going slower anyway. The purpose of a bicyclist’s slow signal is generally to indicate to a following driver that it is unsafe to pass.
  •  “Never ride on the sidewalk – sidewalk crashes are 25 times as frequent than crashes that occur on major streets. Safest are streets with bike lanes.” The 25 times figure is from Moritz’s survey of adult bicyclists. Some other studies show sidewalks to be, whew, only 4 or 5 times as dangerous. The Moritz study shows streets with bike lanes to be slightly safer than others, but no study makes a valid comparison with all other things (available width, traffic volume etc.) being equal. In addition, there are certain particular hazards in bike lanes of which bicyclists should be aware — right-turn conflicts, car doors etc.
  • “Ride in a straight path. If you must pull out into the lane used by drivers, turn around first to be sure the coast is clear.” No, not “turn around” — look back, signal if necessary to get a driver’s cooperation, then look back again to be sure you have it.
  • “If you are stopped at a light or stop sign to the right of a car or truck, the driver might not see you.” Don’t go there. Stop behind the first vehicle. Stopping next to the front of a vehicle can be deadly, as the rear wheels can sweep across your path if it turns right. This is especially so with long trucks and buses.
  • “Try to make eye contact with drivers before you change lanes or turn left.” It helps to see whether the driver is looking toward you, if possible, but the real test is to make sure the driver has yielded to you.
  • “Wear brightly colored clothing in daylight (though I was wearing an electric blue running suit when I was hit and the driver still failed to see me);” She probably had positioned herself out of the driver’s view, or in a direction the driver wouldn’t normally look, or else the driver was lying.
  • “If you cycle at night, you are supposed to have a white headlight and red taillight (preferably a blinking one) so drivers can see you.” Not “supposed to” but the law, which in most states requires a rear reflector and/or steady taillight (though blinking ones work too) and in many states, requires additional reflectors. Additional reflectors are a good idea in any case.
  • “Scan the road 100 feet ahead for possible hazards.” Why 100 feet ahead? Scanning distance depends on speed, road and traffic conditions.