Indiana flashing lights

[monty]

I noticed that recently INDOT has change the flashing sequence on the caution / stop lights at intersections in the Greenfield District.  All have two signal heads and they used to blink alternatively (like a RR crossing signal).  Now they are on the same cycle (bloth flash on and off at the same time in sequence).  I notice that different states use different flash patterns.  Why the change here? 

[Alex]

I noticed that recently INDOT has change the flashing sequence on the caution / stop lights at intersections in the Greenfield District.  All have two signal heads and they used to blink alternatively (like a RR crossing signal).  Now they are on the same cycle (bloth flash on and off at the same time in sequence).  I notice that different states use different flash patterns.  Why the change here?

Changes made per the MUTCD:

2009 Edition Chapter 4L. Flashing Beacons

05 If two horizontally aligned red signal indications are used on an approach for an Intersection Control Beacon, they shall be flashed simultaneously to avoid being confused with grade crossing flashing-light signals.

[monty]

Thanks Alex.  These lights have been on the alternative flash cycle all my life in this area.  So, since the standards cited are from the 2009 edition, it's taken 4 years to get them up to standard.

[Big John]

Thanks Alex.  These lights have been on the alternative flash cycle all my life in this area.  So, since the standards cited are from the 2009 edition, it's taken 4 years to get them up to standard.

Actually, Indiana has their own MUTCD, but must closely match federal standards.  Theirs was implemented in 2011, so it is 2 years late.

And that rule is in the IN MUTCD: http://www.in.gov/dot/div/contracts/design/mutcd/2011rev1/part4l.pdf

[Avalanchez71]

What confusion?

[DaBigE]

Changes made per the MUTCD:

2009 Edition Chapter 4L. Flashing Beacons

05 If two horizontally aligned red signal indications are used on an approach for an Intersection Control Beacon, they shall be flashed simultaneously to avoid being confused with grade crossing flashing-light signals.

And yet they approved the sequence used in a HAWK

[hbelkins]

Kentucky hasn't switched all their flashers over. My district changed them from alternating to simultaneous earlier this year, but some districts still have them flashing alternately.

[Avalanchez71]

I prefer the alternating flashing pattern.  It is more distinctive.

[Alps]

I noticed that recently INDOT has change the flashing sequence on the caution / stop lights at intersections in the Greenfield District.  All have two signal heads and they used to blink alternatively (like a RR crossing signal).  Now they are on the same cycle (bloth flash on and off at the same time in sequence).  I notice that different states use different flash patterns.  Why the change here?

Changes made per the MUTCD:

2009 Edition Chapter 4L. Flashing Beacons

05 If two horizontally aligned red signal indications are used on an approach for an Intersection Control Beacon, they shall be flashed simultaneously to avoid being confused with grade crossing flashing-light signals.

Didn't seem to stop the HAWK signals...