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.

And — though the drawings are intended to show two different ways of riding at the same location, in the “right way” drawing

  • the bike lane magically becomes wider,
  • the parking lane and all the motor vehicles become narrower,
  • the forward bicyclist becomes smaller —

that is, if you Do the Right Thing (according to Gridlock Sam).

(I’ll save detailed comments on dimensions for the end of this posting.)

This is almost as good as Moses parting the Red Sea. Even the fabled Robert Moses had no such powers. The usual traffic engineer is not capable of enlarging and shrinking people or vehicles. Thank you, thank you, Mr. Gridlock Sam!

Now, as to the first, “wrong” drawing: I’m being ornery, so you think I’ll say it is right — right? No. Have a look at this revised drawing in which I’ve corrected the dimensions.


Whether there is a bike lane or not, a bicyclist riding alongside a parked (or double-parked) vehicle needs to stay away from where a door could open, or a pedestrian could walk out. A bicyclist should not suddenly swerve out, but rather, should negotiate with overtaking drivers and merge out early enough to establish right of way.

But, getting back to the underlying issue: unfortunately, double parking is a fact of life in large parts of New York City. Truckers often have no other option for pickups and deliveries — there are no alleys, loading zones, docks etc. to serve most businesses and apartment buildings, there is only street frontage. Double parking, which is illegal almost everywhere, is, unusually, recognized and sanctioned by the rule described on the Gridlock Sam Web page.

If the double-parked truck parks in the bike lane, the bicyclists must merge out into the stream of motor traffic, according to standard vehicular rules. This favors faster riding but is going to be intimidating to many bicyclists on Manhattan avenues and many other NYC arterials, on which the motor traffic is typically either fast, or congested so a bicyclist must filter forward to make reasonable progress. I use the vehicular technique but I can understand that many bicyclists would just avoid the situation.

If the truck is parked outside the bike lane and the bicyclist stays in the bike lane, the bicyclist’s fastest safe speed is about 5 mph in order to avoid collisions with doors from either side, or with someone (most likely the trucker) walking out from where concealed by the truck or a vehicle in the parking lane. The bike lane may also provide a wide enough channel for a vehicle that is “parked in” to get out…or a driver may try, another hazard.

Double parking in New York may not be only one isolated truck — it can go on for an entire block! Bicyclists who understand the hazards can get through safely if slowly, but others will go too fast and/or have poor brakes, and will take risks and some will crash.

A bicyclist who merges around the truck despite the rule may be presumed liable in the event of a crash. That is very unfortunate, and unfair.

Reducing bicyclists’ safe speed to 5 mph is not what I call a bicyclist-friendly solution. Rather, it is a sign of a problem that has not been addressed in any satisfactory way.

The trucker also faces serious impediments — the inability to use a ramp or roller conveyor from the side of the truck without blocking the bike lane, conflicts with bicyclists even when carrying packages by hand, and possible legal tangles.

The speed-positioning rule of the road — stopped traffic at the edge of the street, fastest traffic farthest from the curb — is based on no arbitrary whim, it recognizes and accommodates these concerns. But again, merging out on an urban arterial becomes less attractive for bicyclists with increasing traffic speed and/or volume.

What do I think might be a better solution here?

First of all, the problem isn’t the truckers and it isn’t the bicyclists. Trucking is absolutely indispensable, need I say more. Certainly, trucking could be made more efficient by consolidating deliveries — the Budweiser truck and the Miller’s truck and the Coors truck all serve the same retailers and if these companies worked together, they could save a lot of money, etc. etc. But in any case, the volume of truck traffic isn’t high enough to cause congestion problems.

Bicycling is, aside from its other well-known advantages (low cost, travel times competitive with urban motoring, physical exercise, door-to-door access etc. etc.) one very effective way to free up urban space that otherwise would be gridlocked or occupied by parking.

The problem is the overuse of private passenger vehicles. Potential solutions?

  • I’m disappointed that New York rejected the congestion charge. It has been effective in London.
  • I’ve seen one separate bikeway on a New York avenue which I think works reasonably well — the one on 9th Avenue. Though, let’s not forget, it was expensive to construct and the cheaper separate bikeways in New York don’t work as well. And in any case, truckers are still going to have to carry items across the bikeway, and the loss of a travel lane to motorists makes the added congestion due to double parking even more of a problem. I have several postings about the 9th Avenue Bikeway online:
  • Accommodating north-south bicycle travel in Manhattan is a particularly difficult issue because every avenue is a major arterial, but in the long run, I think that New York would do well to convert one avenue on the west side and one on the east site into bicycle boulevards (motor vehicle access permitted but through travel prevented by barriers and diverters). That solution will only be politically feasible with a substantial reduction in motor traffic — which also would reduce demand for parking and make room for more loading zones. Bicycle boulevards for east-west travel in Manhattan, and elsewhere in New York City, would be somewhat easier to implement.

But don’t hold your breath.

No, maybe do hold your breath, New York also has an air-pollution problem 🙂

New York City laws

I thank Dan Gutierrez for the following observations:

I’d prefer to use the adjacent travel lane to the right of the “double parked” truck, however such behavior is generally illegal in NYC because of the mandatory bikeway law:

“34 RCNY § 4-12(p) Bicycles.

(1) Bicycle riders to use bicycle lanes. Whenever a usable path or lane for bicycles has been provided, bicycle riders shall use such path or lane only except under any of the following situations:

(i) When preparing for a turn at an intersection or into a private road or driveway.

(ii) When reasonably necessary to avoid conditions (including but not limited to, fixed or moving objects, motor vehicles, bicycles, pedestrians, pushcarts, animals, surface hazards) that make it unsafe to continue within such bicycle path or lane.”

Since the City has instructed delivery drivers to park outside the bike lane, would this condition be considered hazardous or the bike lane otherwise “unuseable” per (ii) above by the NYPD?

Math time

Now, for you math heads: In my revised drawing, I took the dimensions to be:

  • parking lane: 7 feet wide
  • bike lane: 5 feet wide
  • cars: 5.5 feet wide
  • pickup truck: 6 feet wide
  • big truck: 8.5 feet wide
  • bicycles: 6.5 feet long (40 inch wheelbase plus 26 inches for the wheel overhang)

The tables below give the dimensions in each of the Gridlock Sam drawings based on the average length of the bicycles, and again on the width of the pickup truck. If the reference is the pickup truck the bicyclists are huge — 11-foot-tall giants. If the reference is the length of the bicycles, the motor vehicles are kiddie-car sized. The dimensions of the lanes also are unusual. In the “wrong” drawing, the parking lane is unusually wide.  In the “right” drawing, so is the bike lane.

Table of dimensions from the “wrong” drawing

The dimensions in pixels are taken from the full-size drawing on the Gridlock Sam site.

Dimension Pixels If bicyclist length 6.5′ If PU truck width 6′
Pkg lane 60 4.5′ 8.4′
Bike lane 40 3.0′ 5.6′
L car width 40 3.0′ 5.6′
Mid car width 34 2.5′ 4.7′
PU truck width 43 3.2′ 6.0′
L bicyclist width 33 2.5′ 4.6′
L bicyclist length 85 6.3′ 11.9′
R bicyclist width 30 2.2′ 4.2′
R bicyclist length 90 6.7′ 12.6′
Big truck width 65 4.8′ 9.1′

Table of dimensions from the “right” drawing

The dimensions in pixels are taken from the full-size drawing on the Gridlock Sam site.

Dimension Pixels If bicyclist length 6.5′ If PU truck width 6′
Pkg lane 55 4.4′ 8.5′
Bike lane 45 3.6′ 6.9′
L car width 36 2.9′ 5.5′
Mid car width 31 2.5′ 4.8′
PU truck width 39 3.1′ 6.0′
L bicyclist width 33 2.7′ 5.1′
L bicyclist length 83 6.7′ 12.8′
R bicyclist width 30 2.4′ 4.6′
R bicyclist length 78 6.3′ 12.0′
Big truck width 60 4.5′ 8.4′

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