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 for 30 mph, except at two-way cross streets where that was not possible.

Information on coordinated signal timing would have to be collected from the City, but at present I can tell that.

  • The signal cycle is approximately 90 seconds.
  • Motorists on 9th Avenue get the green for about half the signal cycle — and so do bicyclists on 9th Avenue crossing streets with traffic from left to right.
  • But on when crossing streets with traffic from right to left, bicyclists get a green for about 1/4 the signal cycle, the first half of the motorists’ through green. This unusually long bicycle green for a sidepath installation with a separate bicycle signal phase is made possible by the separate left-turn lane with its shortened left-turn phase.

Bicyclists may lawfully turn left on their green signal but apparently not on the motorists’ left-turn signal.
As there is no (lawful) cross traffic during the bicycle green, it could work for bicycle traffic in the opposite direction. In fact, some bicyclists do travel (unlawfully) in the opposite direction, but they can’t see the bicycle signal — though concurrent pedestrian signal heads do face them. In any case, the wrong-way riders tend to ignore the signals.

If bicyclists traveling on the bikeway in the intended direction (same as motor traffic on 9th Avenue) merge into the left-turn lane to the right of the bikeway, they interact only with left-turning motor vehicles. Then the bicyclists can proceed for as much of the signal cycle as through-traveling motorists, and left-turning bicyclists can proceed for longer than left-turning motorists. The equal or longer, possible time for bicyclists to proceed is unusual and interesting. However, the merge is unlawful because of New York’s mandatory bike lane law and the near-universal law against using a turn lane for through travel. A change in the law and in markings would significantly add to lawful capacity and reduce travel times.

The average wait for a motorist’s lawful right turn from the right travel lane is approximately 1/4 signal cycle (assuming random arrival). But with the progressive signal timing, the wait is less in practice. As New York’s blanket no-turn-on-red ordinance apparently applies to turns into bicyclists’ right-turn waiting areas ahead of the barriers at cross streets, bicyclists never have a free right turn — they must always wait for one red light or the other. For bicyclists, the wait is 1/2 signal cycle, assuming random arrival, calculated as

  • when arriving on the green, an average of 1/4 signal cycle for the cross-street green.
  • when arriving on the red, an average of 1/4 signal cycle to wait for the bicycle green (unless merging into a left-turn lane at a two-way cross street) and another 1/2 signal cycle to wait for the cross-street green.

So, 1/4 signal cycle wait for 1/2 of the time and 3/4 for the other 1/2 of the time, and an average of 1/2.

The Avenue is designed for access to both sides by motorists (with the parking spaces between the bikeway and travel lanes on the left side) but only as a through route for bicyclists, as the bikeway does not provide access to destinations along the right side of 9th Avenue. With mostly one-way cross streets in alternating directions, bicyclists have to travel as far as two blocks in the regular travel lanes, or walk on sidewalks, to reach these destinations lawfully. With New York’s mandatory bike lane law, there is an issue that a bicyclist involved in a crash when lawfully riding to a destination on the right side of the Avenue may still be held at fault, especially if killed or unable to remember the purpose of the trip.

There is also the issue of how to transition from the bikeway to the travel lanes of 9th Avenue.

  • A box turn is one option, and is lawful with a total of a 3/4 cycle’s waiting (average 1/4 signal cycle at the right-turn waiting area, then 1/2 for the signal to turn green for 9th Avenue before turning left);
  • Proceeding from the bikeway to the left side of the left travel lane, then merging right is another option requiring 1/4 signal cycle average waiting This, too, is consistent with normal patterns of traffic flow and can be done at a cross street with traffic in either direction or both directions.

Some signs, signals, markings and barriers do not conform to standard specifications. Some of these could raise questions about right of way in the event of a crash. Some specific examples:

  • Motorist’s left-turn arrow may be in conflict with pedestrian interval for cross street (Issue raised by Bob Shanteau). The MUTCD does not allow a pedestrian movement concurrent with a turn-only signal.
  • Some line widths are nonstandard.
  • Striped median extension (on 9th Avenue north of 31st Street) is in the usual location for a bike lane.
  • Buffers (on Hudson Street) make it unlawful for bicyclists to merge out of the bike lane.
  • The manual on Uniform Traffic control Devices, the US standard for signs, signals and markings, indicates that a bike lane should not be placed behind a barrier and a bike path should be separated by at least 5 feet, or a barrier. A question of definition arises, as this facility transitions from one to the other repeatedly, and painted median widths below 5 feet exist.
  • The MUTCD as of yet includes no specification for separate bicycle signals.

One Response to Technical and legal issues with the NYC 9th Avenue bikeway

  1. Pingback: John S. Allen's Bicycle Blog » Gridlock Sam’s magic powers!

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