Mystery traffic signals at former Drum Hill Rotary, MA

[Michael Moroney]

I noticed this week that the rebuilt former "Drum Hill Rotary" at
the junction of US 3 and MA 4 in Chelmsford MA has traffic signals
controlling traffic leading _out_ of the square, at least on MA 4,
in both directions. They are located at about the point where the
lane from the square joins the lane coming the other way to form the
two lane road. What is their purpose? They can only keep people from
entering the two lane roads leading away, and any traffic stopped at the
light would back up and block the square. There is no cross street/
driveway or even pedestrian crosswalks, nor is there any light stopping
traffic the other way (there is, of course, a light a little past there
at the corners of the square itself) I think there is a similar light on
the other two roads (Old Westford Rd and Drum Hill Rd) but am unsure.
Construction isn't finished there but the lights look permanent.

For those not familiar with it: Think of a square with traffic flowing
around it counterclockwise, and a grade separated freeway crossing the
middle of the square horizontally (US 3 is approximately E-W there), with
diamond ramps to/from the freeway from/to the corners of the square, and 4
2-lane roads leading northish/southish from the corners of the square. A
traffic light on each corner of the square, and just before each of these
lights/corners at the US 3 onramps a lane veers right and becomes one lane
of MA 4. Where this lane meets traffic coming the other way (where the
double yellow line starts) is where the mystery lights are. Every time
I've seen them those lights were green.

Aside: The left turn arrows at the corners are at 45 degree angles. Is
that allowed according to the MUTCD?

[John F. Carr]

Post by Michael Moroney
Aside: The left turn arrows at the corners are at 45 degree angles. Is
that allowed according to the MUTCD?

"Arrows [on traffic signals] shall be pointed:

A. Vertically upward to indicate a straight-through movement;
B. Horizontally in the direction of the turn to indicate a turn
at approximately or greater than a right angle; and
C. Upward with a slope at an angle approximately equal to that
of the turn if the angle of the turn is substantially less
than a right angle."

MUTCD section 4D.16
http://mutcd.fhwa.dot.gov/HTM/2003r1/part4/part4d.htm#section4D16

[Jim]

Post by Michael Moroney
I noticed this week that the rebuilt former "Drum Hill Rotary"
at the junction of US 3 and MA 4 in Chelmsford MA has traffic
signals controlling traffic leading _out_ of the square, at
least on MA 4, in both directions. They are located at about
the point where the lane from the square joins the lane coming
the other way to form the two lane road. What is their purpose?
They can only keep people from entering the two lane roads
leading away, and any traffic stopped at the light would back up
and block the square. There is no cross street/ driveway or
even pedestrian crosswalks, nor is there any light stopping
traffic the other way (there is, of course, a light a little
past there at the corners of the square itself)

Modern will be putting in pedestrian crosswalks this spring/summer.

For those of you who don't know the area, Chelmsford High School
(and a fair amount of residential) is near there, south of Route 3,
and there is a lot of retail just north of Route 3. There are
already a lot of people - including kids - who are walking from the
school to the retail area, through the Drum Hill Square.

Jim
(Heh, just looked at this area on mapquest.com and the place where
the Wal-Mart is now is labeled "Caldor Mall". Caldor's been gone,
what, a decade?)

[Bryan]

Here's a link to a drawing of the interchange:
Loading Image...

Bryan

[Michael Moroney]

Post by Jim

Post by Michael Moroney
I noticed this week that the rebuilt former "Drum Hill Rotary"
at the junction of US 3 and MA 4 in Chelmsford MA has traffic
signals controlling traffic leading _out_ of the square, at
least on MA 4, in both directions.

...

Post by Jim
Modern will be putting in pedestrian crosswalks this spring/summer.
For those of you who don't know the area, Chelmsford High School
(and a fair amount of residential) is near there, south of Route 3,
and there is a lot of retail just north of Route 3. There are
already a lot of people - including kids - who are walking from the
school to the retail area, through the Drum Hill Square.

OK that would make sense if there are signals on MA 4 coming the other
way (before entering the square) that haven't been installed.
I forgot about the school.

re Bryan and the drawing of the interchange at:
http://www.widen3.com/images/proj_drumhill.jpg : That doesn't show either
the mystery signals nor crosswalks but it does show how a right turn lane
splits off at the upper left and lower right corners to form MA 4 and
there is no car traffic that can interfere with it. (there is at the
other corners)

[David Chesler]

Post by Jim
Modern will be putting in pedestrian crosswalks this spring/summer.

What is that in people years?