No yellow change interval at a traffic signal.

[tradephoric]

Here is an example of a traffic signal with no yellow change interval.  At 0:48 in the video, the permissive flashing red ball goes straight into a solid red ball.

[hotdogPi]

Why do the green lights look blue?

[tradephoric]

I'm pretty sure it's just the camera I'm using.  The picture quality isn't very good and the picture will randomly defocus for no apparent reason.

[Big John]

I've ran across a few traffic signals where the green looked blue, but not since they were switched to LED lights.

[signalman]

Delaware's flashing red arrow signals do the same thing.  They go from a flashing red arrow to solid red ball with nothing in between.  (On a side note: not sure why DE uses a red ball for them since DelDOT is so fond of arrows in all colors and directions.)

[tradephoric]

Is that a common setup in Delaware?  Nearly all Michigan flashing red balls will have lagging left turns that cycle regardless of demand to prevent this scenario from occurring.  The only place i've seen the scenario where the flashing red ball will go straight into a solid red ball is in the Grand Rapids area. 

[hbelkins]

You're supposed to stop at a flashing red ball anyway, so I don't know why a yellow would be necessary.

[Brandon]

You're supposed to stop at a flashing red ball anyway, so I don't know why a yellow would be necessary.

A typical flashing red ball.  In practice, even for cops, these are treated more as a yield.  You pull into the intersection and wait to complete your turn when traffic is clear.  The problem with the leading ones is that traffic will then have to clear after the signal turns red.  That's why the lagging protected turns are superior.

[jeffandnicole]

Is that a common setup in Delaware?

Yes. The typical setup in Delaware is a "T" looking light as follows:

RA  RL    (Red Left Arrow, Red Light)
   YA       (Yellow Left Arrow)
   GA       (Green Left Arrow)

On some occasions, it'll be a 3 light setup, with all lights being left arrows.

There is no yellow phase between the flashing and the solid red ball. And as mentioned, the yellow should be pretty pointless...At a red light - regardless if it's flashing or solid, you're not supposed to go beyond the stop line until you can safely make your turn.  Only on a green light are you permitted to pass the stop line and wait for a break in traffic.  If local practice is different (which it is in Delaware), then it's all fine and good until someone gets in an accident - the person that is beyond the stop line at a flashing red light will almost always be at fault.

The problem with the leading ones is that traffic will then have to clear after the signal turns red.  That's why the lagging protected turns are superior.

Again, per the law, opposing traffic should be slowing and stopping at a yellow, not flying thru the intersection until the last possible nanosecond.  Traffic intending on turning left should be able to do so before the light turns red, and if they can't the all-red clearance phase exists for that reason.   The problem with a lagging protected turn is most sensors only know if a car is within a car length or 2 of the stop line.  Most lagging protected turns are set at a maximum green to help clear out an entire turning lane's worth of traffic, regardless if 1 car or 10 cars were in that lane.

[PHLBOS]

The only time I've seen that flashing red going straight to solid red was at an old signal for a right-turn movement from West Shore Drive to MA 114 westbound (Lafayette St.) in Marblehead.  The change would only occur when a pedestrian pushes the button for the WALK signal.  This signal originally had a green arrow that was on for all except the WALK signal phase; it was likely changed (to the flashing red) due to accidents involving merging traffic blasting through.

The signals in question were completely replaced in 1980 with green arrows again; but would change to red more frequently (not just for WALK signals).

[tradephoric]

I was surprised to see a signal operate like this since it appears to be specifically banned in the MUTCD (it doesn't address the flashing red ball, but it does mention the flashing red arrow).  So if there's a signal in Delaware that goes straight from a flashing red arrow to a solid red, that would violate the following MUTCD provision correct?

Section 4D.26  Yellow Change and Red Clearance Intervals
Standard:
01   A steady yellow signal indication shall be displayed following every CIRCULAR GREEN or GREEN ARROW signal indication and following every flashing YELLOW ARROW or flashing RED ARROW signal indication displayed as a part of a steady mode operation.  This requirement shall not apply when a CIRCULAR GREEN, a flashing YELLOW ARROW, or a flashing RED ARROW signal indication is followed immediately by a GREEN ARROW signal indication.

Not warning drivers that a permissive phase is ending seems like a dangerous situation that should be avoided.

[M3019C LPS20]

A tad bit off-topic, but I find it interesting that the pedestrian signal at the corner continued to flash (hand) after the traffic signals changed from amber to red.

[JREwing78]

This is an older installation; a current configuration (at least in Michigan) would have a 4-light sequence:

-----------------------------------------------
|                                                            /|\
\|/                                                            |
Green -> flashing Yellow Arrow -> Yellow -> Red

[tradephoric]

A tad bit off-topic, but I find it interesting that the pedestrian signal at the corner continued to flash (hand) after the traffic signals changed from amber to red.

Nice catch.  It's quite common in Michigan to see the pedestrian signal count down straight through the yellow and all red (I.E no pedestrian buffer).  Now that the 2009 MUTCD requires a 3 second buffer, these signals are slowly being converted to adhere to the new standards. 

[tradephoric]

You're supposed to stop at a flashing red ball anyway, so I don't know why a yellow would be necessary.

Assume a driver is stopped at the stop bar waiting for a safe gap in traffic during the flashing red ball.  A safe gap in traffic comes up, and the driver proceeds to punch the gas to start making their left.  What if the flashing red ball changes to a solid red ball just as the driver places their foot on the gas?  The driver is essentially running a red light in this scenario.  A yellow change is necessary to prevent a scenario like this from occurring. 

[jeffandnicole]

You're supposed to stop at a flashing red ball anyway, so I don't know why a yellow would be necessary.

Assume a driver is stopped at the stop bar waiting for a safe gap in traffic during the flashing red ball.  A safe gap in traffic comes up, and the driver proceeds to punch the gas to start making their left.  What if the flashing red ball changes to a solid red ball just as the driver places their foot on the gas?  The driver is essentially running a red light in this scenario.  A yellow change is necessary to prevent a scenario like this from occurring. 

If they're stopped at a flashing red arrow when the light turns yellow, they're not supposed to enter the intersection anyway, even if that sequence and the gap occurs at the same time.

[rawmustard]

Assume a driver is stopped at the stop bar waiting for a safe gap in traffic during the flashing red ball.  A safe gap in traffic comes up, and the driver proceeds to punch the gas to start making their left.  What if the flashing red ball changes to a solid red ball just as the driver places their foot on the gas?  The driver is essentially running a red light in this scenario.  A yellow change is necessary to prevent a scenario like this from occurring.

The driver is supposed to have already moved into the intersection (moving in front of the stop bar) to wait to make his turn. That way, if the light becomes solid red, the completion of the turn is legal.

[jeffandnicole]

Assume a driver is stopped at the stop bar waiting for a safe gap in traffic during the flashing red ball.  A safe gap in traffic comes up, and the driver proceeds to punch the gas to start making their left.  What if the flashing red ball changes to a solid red ball just as the driver places their foot on the gas?  The driver is essentially running a red light in this scenario.  A yellow change is necessary to prevent a scenario like this from occurring.

The driver is supposed to have already moved into the intersection (moving in front of the stop bar) to wait to make his turn. That way, if the light becomes solid red, the completion of the turn is legal.

You're thinking of it in terms of yielding at a green light or a flashing yellow light.

At a flashing red arrow, you re supposed to remain stopped at the stop line until there's a gap in traffic, if that gap occurs.

[NE2]

At a flashing red arrow, you re supposed to remain stopped at the stop line until there's a gap in traffic, if that gap occurs.

[citation needed]
It seems that one should apply the same rules as for a flashing red ball/stop sign/turn on red: stop at the stop line, then inch forward if you wish, but don't conflict with other traffic until you can complete the movement.

[tradephoric]

Assume a driver is stopped at the stop bar waiting for a safe gap in traffic during the flashing red ball.  A safe gap in traffic comes up, and the driver proceeds to punch the gas to start making their left.  What if the flashing red ball changes to a solid red ball just as the driver places their foot on the gas?  The driver is essentially running a red light in this scenario.  A yellow change is necessary to prevent a scenario like this from occurring.

The driver is supposed to have already moved into the intersection (moving in front of the stop bar) to wait to make his turn. That way, if the light becomes solid red, the completion of the turn is legal.

Is the driver suppose to come a complete stop at the stop bar before moving into the intersection?  If so (and that is what is taught) the driver is not yet into the intersection when they come to a complete stop.  After coming to a complete stop (vehicle still at the stop bar) the driver sees that there is a safe gap in traffic and punches the gas to complete the left turn.  Just as they punch the gas the signal changes from a flashing red ball to a solid red ball.  That driver is running a red light. 

It's really easy to run a red light when there isn't a yellow.

[Kacie Jane]

I don't think I've ever encountered a light that is sometimes a flashing red and sometimes a solid red, so I can't speak from personal experience.  But one thing intrigues me about this discussion.  The argument seems to be that you need the yellow phase so that a motorist looking for a gap in traffic doesn't get caught by the flashing red going solid and knows they're not allowed to go anymore.

But if the motorist's eyes are on cross/oncoming traffic looking for a gap -- and not on the light, which is why they didn't see it go solid -- then I'm not sure I'd count on them to catch the yellow phase either.

[Revive 755]

I was surprised to see a signal operate like this since it appears to be specifically banned in the MUTCD (it doesn't address the flashing red ball, but it does mention the flashing red arrow).  So if there's a signal in Delaware that goes straight from a flashing red arrow to a solid red, that would violate the following MUTCD provision correct?

Section 4D.26  Yellow Change and Red Clearance Intervals
Standard:
01   A steady yellow signal indication shall be displayed following every CIRCULAR GREEN or GREEN ARROW signal indication and following every flashing YELLOW ARROW or flashing RED ARROW signal indication displayed as a part of a steady mode operation.  This requirement shall not apply when a CIRCULAR GREEN, a flashing YELLOW ARROW, or a flashing RED ARROW signal indication is followed immediately by a GREEN ARROW signal indication.

I don't think Delaware is supposed to be using the flashing red ball per the MUTCD, and should always be using a flashing red arrow for the left turns.

On a related note, there is an active experiment in Austin, TX, for a flashing red arrow that goes to a steady red arrow without a yellow arrow when an opposing left turner is present:
http://mutcd.fhwa.dot.gov/reqdetails.asp?id=828

[jeffandnicole]

I was surprised to see a signal operate like this since it appears to be specifically banned in the MUTCD (it doesn't address the flashing red ball, but it does mention the flashing red arrow).  So if there's a signal in Delaware that goes straight from a flashing red arrow to a solid red, that would violate the following MUTCD provision correct?

Section 4D.26  Yellow Change and Red Clearance Intervals
Standard:
01   A steady yellow signal indication shall be displayed following every CIRCULAR GREEN or GREEN ARROW signal indication and following every flashing YELLOW ARROW or flashing RED ARROW signal indication displayed as a part of a steady mode operation.  This requirement shall not apply when a CIRCULAR GREEN, a flashing YELLOW ARROW, or a flashing RED ARROW signal indication is followed immediately by a GREEN ARROW signal indication.

I don't think Delaware is supposed to be using the flashing red ball per the MUTCD, and should always be using a flashing red arrow for the left turns.

On a related note, there is an active experiment in Austin, TX, for a flashing red arrow that goes to a steady red arrow without a yellow arrow when an opposing left turner is present:
http://mutcd.fhwa.dot.gov/reqdetails.asp?id=828

It is ironic that, in a state that values those arrows, they use a solid red ball where it's only possible to turn left (making the u-turn).