Overly Long Mastarms

[Brandon]

This is something I've noticed for a long time in NE Illinois.  A lot of mastarms at traffic signals are much longer than they need be.  Take this example from IL-22 (Half Day Rd) and Riverwoods Rd in Lake County, Illinois:



The mastarm goes way past the five light tower.  Is there a reason for this?

[hotdogPi]

Maybe there used to be another traffic light there?

Maybe shorter sizes (that are still long enough) don't exist?

[Brandon]

Maybe there used to be another traffic light there?

Maybe shorter sizes (that are still long enough) don't exist?

No, these even appear on new installations with no signal having ever been there or planned to be there.  And I know shorter sizes exist.  Check out the mastarm on the other side of the intersection.

[Scott5114]

Maybe there used to be another traffic light there?

Maybe shorter sizes (that are still long enough) don't exist?

No, these even appear on new installations with no signal having ever been there or planned to be there.  And I know shorter sizes exist.  Check out the mastarm on the other side of the intersection.

They look like the same length to me, but on the other side, the signal heads are further out along the mastarm.

[Big John]

The agency may do that if they think more heads are needed sometime in the future, such as a turn on arrow only situation with added furure traffic.

[roadfro]

Mast arms tend to come in predetermined lengths. Sometimes the length might be a little long for what is needed for the innermost lane signal head, but going to the next size down would be too short--thus they arrange the tenons at the needed points and have extra length on the mast. Not saying that is the case with this location, but it's a plausible answer.

Other explanation would be that the extra length is reserved for a potential future signal head (like adding a dedicated left turn signal in the future). That doesn't seem to be the case here, otherwise the 5-section tower would be at the far end.

One other explanation could be that the mast arm was recycled from another location...

[Brian556]

Maybe shorter sizes (that are still long enough) don't exist?

Metal can be cut. They could cut the longer ones to the correct length, then weld a custom cut endcap on the if if it is needed.

[Big John]

Other explanation would be that the extra length is reserved for a potential future signal head (like adding a dedicated left turn signal in the future). That doesn't seem to be the case here, otherwise the 5-section tower would be at the far end.

The 5-section tower serves through and left-turning traffic.  If they decide to make it a separate left turn on arrow only, they would replace the 5-section tower with a 3-section signal for through traffic and add a 3-section left turn signal at the end of the mast arm.

[Brandon]

Other explanation would be that the extra length is reserved for a potential future signal head (like adding a dedicated left turn signal in the future). That doesn't seem to be the case here, otherwise the 5-section tower would be at the far end.

The 5-section tower serves through and left-turning traffic.  If they decide to make it a separate left turn on arrow only, they would replace the 5-section tower with a 3-section signal for through traffic and add a 3-section left turn signal at the end of the mast arm.

That's not commonly done in IDOT District 1 though.  When they have the 5-section tower, they're usually done.  I've seen overly long mastarms in places where there will neevr be another signal to the left:

I-55 and US-30, Joliet.

[mass_citizen]

perhaps it has to do with the structural design. depending on foundation design, wind loading, etc. the longer arm could serve to balance the structure.

[Scott5114]

Maybe shorter sizes (that are still long enough) don't exist?

Metal can be cut. They could cut the longer ones to the correct length, then weld a custom cut endcap on the if if it is needed.

Someone has to be paid to do that. It's easier and cheaper to just leave it with the extra sticking out, especially since the vast majority of the public wouldn't notice the aesthetic touch (and would probably consider it a waste of tax money).

[jeffandnicole]

Maybe shorter sizes (that are still long enough) don't exist?

Metal can be cut. They could cut the longer ones to the correct length, then weld a custom cut endcap on the if if it is needed.

Someone has to be paid to do that. It's easier and cheaper to just leave it with the extra sticking out, especially since the vast majority of the public wouldn't notice the aesthetic touch (and would probably consider it a waste of tax money).

A typical traffic light installation will cost $100,000 or so...and that's when no modifications to the intersection are necessary. Start widening the intersection, adding in sidewalks, curbs, curb cuts, etc, and the expense grows quickly.

Cutting metal and putting a cap on it?  Pennies, compared to the overall cost.

Most of the time though, the project is designed and the determination of the length of the pole is made well before the project is put out to bid.  Continuing with what Mass Citizen stated, if 3 sides of that intersection needed that length pole, the design team may have decided to cut costs (or got lazy) and just use the same design for the 4th pole, rather than doing the more proper thing and design the structure specifically for that leg of the intersection.

[Alps]

One other thought: If you have 7 30-footers and 1 20-footer on a job, there's a chance it's actually cheaper to just order 8 30-footers instead.

[SignBridge]

These extra-length uncut mast-arms are common in Northern Virginia too. Especially in Fairfax and Loudoun Counties. I think they look ridiculous. Cut to size looks far more professional.

[cpzilliacus]

These extra-length uncut mast-arms are common in Northern Virginia too. Especially in Fairfax and Loudoun Counties. I think they look ridiculous. Cut to size looks far more professional.

Consider this in Fairfax County, which obviates the need for any mast arm, short, long or cut to size.

[PColumbus73]

These extra-length uncut mast-arms are common in Northern Virginia too. Especially in Fairfax and Loudoun Counties. I think they look ridiculous. Cut to size looks far more professional.

Consider this in Fairfax County, which obviates the need for any mast arm, short, long or cut to size.

I'd consider that overkill

[xcellntbuy]

These extra-length uncut mast-arms are common in Northern Virginia too. Especially in Fairfax and Loudoun Counties. I think they look ridiculous. Cut to size looks far more professional.

Consider this in Fairfax County, which obviates the need for any mast arm, short, long or cut to size.

I'd consider that overkill

We have a couple of those big behemoths in Broward County, Florida, painted completely black.  One is located at Broward Blvd. and North/South University Drive in Plantation and another at Sunrise Blvd. and North University Drive on the Sunrise/Plantation city line.  Undoubtedly there are others.  They are just awful to look at.

[SignBridge]

I saw one of those myself near Lansdale, Pennsylvania, on Route-309.

[2Co5_14]

The extra length of mastarm is common in the Atlanta area also.  Additionally, as in the examples below, sometimes the pole itself is taller than it needs to be.  It is extremely rare to have luminaires mounted on the signal poles here, so that doesn't appear to be the intent in these cases.

https://maps.google.com/maps?q=Cherokee+Street+Northwest+%26+Shiloh+Rd+NW,+Kennesaw,+GA&hl=en&ll=34.05097,-84.595156&spn=0.000018,0.011684&sll=34.041135,-84.603348&sspn=0.059601,0.09347&hnear=Shiloh+Rd+NW+%26+Cherokee+St+NW,+Kennesaw,+Cobb,+Georgia+30144&t=m&z=17&layer=c&cbll=34.051097,-84.595074&panoid=FWXQeSFZXEo9Qj6glWxIYg&cbp=12,57.39,,0,2.98

https://maps.google.com/maps?q=10th+Street+%26+W+Peachtree+St,+Atlanta,+GA&hl=en&ll=33.781733,-84.387832&spn=0.000018,0.011684&sll=33.781823,-84.37942&sspn=0.014946,0.023367&hnear=West+Peachtree+St+NW+%26+10th+St+NW,+Atlanta,+Fulton,+Georgia+30309&t=m&z=17&layer=c&cbll=33.781557,-84.38781&panoid=gXlzp64Q-XYr5zmEpcXb0g&cbp=12,345.6,,0,-4.19

[roadfro]

These extra-length uncut mast-arms are common in Northern Virginia too. Especially in Fairfax and Loudoun Counties. I think they look ridiculous. Cut to size looks far more professional.

Consider this in Fairfax County, which obviates the need for any mast arm, short, long or cut to size.

I'd consider that overkill

Nevada has similar setups in a few places in the Las Vegas area, although these are almost always of the monopole design instead of the large truss design linked above.

Such setups are commonly used at overly wide intersections where the typical mast arm setup would be too far away from the stop line according to MUTCD & design standards. These are often intersections along wide, angled highways with another street on a normal grid line (i.e. several along roads intersecting SR 160 in SW Las Vegas Valley and a few on SR 146 in Henderson), and are seen at some SPUIs with the signal above the freeway.

However, the intersection in the original quote doesn't seem to be all that wide as to warrant using the truss like this--I've seen wider intersections in Las Vegas with a conventional setup...

[6a]

Saw this today, Alum Creek & Williams Rds, Columbus. It's a widening project but that part is done. The only thing I can think is the large truck traffic turning right towards me in this view, but the other poles are still in the way.

[Big John]

^^ there may be buried utility lines or sewerage pipes in the way so pushing the base away from those looked to be a solution.