3 way stop with only a stop bar and red flashing lights, no stop signs

[Mohkfry]

I figured someone with knowledge in the MUTCD could answer this. This is an intersection in the Miller neighborhood of Gary, IN. This is a 3 way (4-way based on the signal arrangement) stop on a rarely traveled side street that features only flashers and stop bars, but no stop signs what-so-ever. Is this allowed in the MUTCD, or are stop signs required here along with the flashing lights? This is the only installation I have ever seen set up like this.

The street view link is from 2013, but the set up is still the same today. There are still no stop signs on any of the 3 approaches.

Here's the intersection in question.

https://www.google.com/maps/@41.6183426,-87.2370435,3a,75y,183.21h,71.78t/data=!3m6!1e1!3m4!1sTZXEbhLELmahxj6bU9Gf6Q!2e0!7i13312!8i6656!6m1!1e1

[Big John]

Is this allowed in the MUTCD, or are stop signs required here along with the flashing lights? This is the only installation I have ever seen set up like this.

Not allowed.

2009 MUTCD Chapter 4L:

Section 4L.02 Intersection Control Beacon

04 A STOP sign shall be used on approaches to which a flashing red signal indication is displayed on an Intersection Control Beacon (see Section 2B.04).

http://mutcd.fhwa.dot.gov/htm/2009/part4/part4l.htm

[UCFKnights]

Are the signals alternating or flashing together? Street view makes it appear they are alternating.

[Mohkfry]

Are the signals alternating or flashing together? Street view makes it appear they are alternating.

They're alternating.