Traffic Signal Timing: Burnett at Rt 55 Clearance Interval

Back in the day, John Forester’s Effective Cycling defined how vehicular bicycling should be done; our now-fragile comb-bound 1980 Third Printing of the 1978 Third Edition still has a place of honor on our bookshelves. I recently discovered his analysis of how traffic signal timing should work online, which says I’ve drawn the wrong conclusions from my observations of the absurdly short green / yellow / red cycle on Burnett Blvd at Rt 55, just in front of NYS DOT’s Region 8 headquarters.

The phasing sequence that is required by current traffic law is as follows:

1. Green, which may be very short when only one vehicle is waiting

2. Yellow, of only sufficient duration to allow a stop from maximum legal speed before entering the intersection

3. Red (a 4-way red), for sufficient additional time for traffic to clear the intersection before the conflicting green appears.


With that in mind, here’s how his analysis stacks up against one of our recent trips through the intersection. The four-digit number in the picture titles gives the time in frames at 60 frame/sec.

We’re stopped one car length behind a long trailer of paving equipment sporting an Iowa license plate. The driver has stopped with the trailer straddling the lane divider line, so we cannot determine which way he will turn. Because we no longer trust turn signals, despite the trailer’s blinking left signal, we will not pull up beside it in the right lane.

Frame 0127, T = 0 s, Δt = 0 s: The signal has just turned green:

Burnett Opposing Green - AS30V - 2020-06-26 - 0127
Burnett Opposing Green – AS30V – 2020-06-26 – 0127

Frame 0264, T = 2.28 s, Δt = 2.28 s: The trailer has started moving and Mary is rolling behind it, with her foot just coming off the ground:

Burnett Opposing Green - AS30V - 2020-06-26 - 0264
Burnett Opposing Green – AS30V – 2020-06-26 – 0264

Frame 0721, T = 9.9 s, Δt = 7.6 s: The signal turns yellow, after DOT’s additional five seconds of green; previously, we had five seconds and would have been able to stop. We’re accelerating as hard as we can, but Mary has barely passed the stop line:

Burnett Opposing Green - AS30V - 2020-06-26 - 0721
Burnett Opposing Green – AS30V – 2020-06-26 – 0721

Of course, entering an intersection on a stale yellow is undoubtedly unwise. It is not so unwise for someone traveling fast, because that person may well clear the intersection before the conflicting traffic starts. It is much more unwise for someone traveling slowly, but it is done and it is lawful.

Forester, ibid.

We’ve traveled about three car lengths in the seven seconds since the trailer started moving. Our bikes will sometimes trigger the signal if we’ve stopped in exactly the right spot over the unmarked sensor loops, but we have never observed our bikes retriggering the signal to lengthen the green or yellow phases as we ride through the intersection.

NYS DOT apparently expects us to stop abruptly when the signal goes yellow, wherever we may be with respect to the stop line and regardless of how fast we may be moving. In fact, given what you’re about to see, we’re expected stop on green to ensure we can start from the stop line during the next green signal.

Frame 0983, T = 14.2 s, Δt = 4.4 s: The signal turns red. The trailer is visible on the left, beyond the median signage, but we haven’t reached the middle of the intersection. I’m lined up with the rightmost lane of westbound Rt 55 and Mary is about in the center lane. The white car on our right is stopped, the black car is slowing to a stop:

Burnett Opposing Green - AS30V - 2020-06-26 - 0983
Burnett Opposing Green – AS30V – 2020-06-26 – 0983

Frame 1101, T = 16.2 s, Δt = 2.0 s: The opposing signal goes green for Rt 55 traffic, while we’ve barely reached the middle of the intersection:

Burnett Opposing Green - AS30V - 2020-06-26 - 1101
Burnett Opposing Green – AS30V – 2020-06-26 – 1101

Frame 1205, T = 18.0 s, Δt = 1.8 s: I’m lined up with the median, Mary’s in the center lane of eastbound Rt 55, putting us squarely in front of drivers who may be unable to see us through the stopped cars. The drivers to our left are, fortunately, waiting, unlike a previous crossing:

Burnett Opposing Green - AS30V - 2020-06-26 - 1205
Burnett Opposing Green – AS30V – 2020-06-26 – 1205

Frame 1440, T = 21.9 s, Δt = 5.7 s: After 22 seconds, we’ve cleared the intersection and are proceeding eastbound on Rt 55:

Burnett Opposing Green - AS30V - 2020-06-26 - 1440
Burnett Opposing Green – AS30V – 2020-06-26 – 1440

Forester observes the all-red phase must be lengthened to allow cyclists to clear the intersection. Right now, two seconds isn’t enough. Ten seconds would suffice for a pair of reasonably fit, albeit aging, cyclists.

This system fails to provide the required safety in the case of bicycles for three opposite reasons.

1. Bicycles are small and are harder to see. In particular, the most visually impressive part of the bicycle and rider is low down where it is easily shielded from view by the hoods of motor vehicles. Sometimes the only part of the cyclist that can be seen by drivers waiting at the stop line with other vehicles on their left is the head of the cyclist.

2. The cyclist crossing a typical intersection is close to the fronts of the line of cars waiting at the stop line on the cyclist’s right. This is not good judgement on the part of the cyclist, but so much emphasis has been put on staying far right that this position is typical.

3. The cyclist who is traveling slowly, or, more importantly, is starting from a minimum-duration green, is barely into a wide intersection when the conflicting green appears.

The result is a car-bike collision as one of the vehicles in the lanes nearest the curb starts up, or speeds up, and hits the cyclist who suddenly appears in front of it.

Forester, ibid.

I’ve had a DOT engineer tell me, sneeringly, that they don’t design facilities for “professional cyclists”, which commuting to work evidently made me; he was not, however, a “professional driver” even though he used a car for a similar purpose. It’s obvious DOT doesn’t design facilities for “ordinary” cyclists, either, and the evidence suggests they don’t design facilities for cyclists, period, full stop.

I still want someone from NYS DOT to explain how this “makes our highway systems safe and functional for all users“, perhaps by bicycling with us through the intersection a few times, but I’ve never gotten a response, let alone an answer, to anything I’ve ever sent their way.

9 thoughts on “Traffic Signal Timing: Burnett at Rt 55 Clearance Interval

  1. Could you have rolled up beside the Iowa truck and knocked on the door to establish eye-contact and indicate your intention to turn left? The crosswalk-curb cut provides an exit path if necessary…

    I burn five bright flashing daytime lights and still ride as if I’m invisible… Conspicuity and the First Law.

    1. I could visualize being at the trailer’s wheels when he started turning left, whereupon the trailer’s butt end would sweep me off to the right. Better to stay back and take our chances with the signal timing.

      IMO, DOT could add five seconds to the all-red clearance time of every intersection in the state and not one driver would notice.

  2. You’ve said that the bikes only sometimes trigger the light. I’m curious whether you’ve looked at methods to trigger the car sensors in the road? A quick search popped up the following product, which legit. ANd they claim it’s legal in the US. Heck, maybe it’s an opportunity for a DIY project?

    1. They’re either ignorant of or deliberately misrepresenting the rules & regulations. I suspect the latter, because a casual search turns up showstoppers they should know about.

      An explainer from the FCC concerning Part 15 rules for transmitters:

      Click to access oet63rev.pdf

      Money quote: “Although an operator does not have to obtain a license to use a Part 15 transmitter, the transmitter itself is required to have an FCC authorization before it can be legally marketed in the United States.”

      There’s also the notion of deliberately interfering with traffic control devices, which a casual search suggests is a Very Bad Idea. This is for West Virginia, although I’m sure other states aren’t much different:

      Money quote: “The possession or use of … any type of infrared or electronic device capable of changing a traffic control signal, by anyone other than the operator of an authorized emergency vehicle, is prohibited”

      So, yes, I’ve looked at such things and, no, I’m not going there.

      1. In the ’70s, I had a Honda 350 motorcycle that was invisible to the California traffic sensor loops. The 350 sized bike was pretty common back then, but CalTrans and the municipalities weren’t interested in dealing with it. Bicycles were invisible to sensors through the ’90s.

        Around here, they seem to be using a vision system for many of the city’s traffic signals, though I’ve seen the occasional loop.

        1. The loops on Spackenkill ignore at least some motorcycles; I assume the riders have given up trying to get any official attention, as have I.

          Oddly, the “trial” vision system on Zack’s Way (sometimes) thinks we’re a weird stretch limo and changes the signal for us. If only they’d apply that logic consistently …

    1. Stand back, he’s using math!

      I remember that story when it started and I’m glad to know the right answer came out in the end. The messenger-shooting (putting it mildly) he encountered seems typical; it’s easier than actually doing something useful.

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