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.

Forester: https://johnforester.com/Articles/Facilities/traffsig.htm

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:

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:

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:

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:

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:

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:

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:

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.