Can you explain why the red arrow and a yellow arrow lights at 44th & McIntyre were on at the same time?

JEFFERSON COUNTY, Colo — Kimberly from Denver writes, “What's driving you crazy? My friends and I were at McIntyre at 44th on our way to Golden when we saw this weird traffic signal with the red arrow and a yellow arrow lights on at the same time. We were unsure of what to do since we have never seen this before. Is this just a malfunctioning signal or is this something new?”

What you saw was an isolated glitch with the signal due to what I was told was some substandard internal wiring. Jefferson County public works tells me after other drivers reported this same problem, the county sent signal technicians to disable the flashing yellow arrow which removed the conflict and resolved the issue.

Public Works made another change to the signage shortly after you sent me that picture. The signal used to allow north and southbound McIntyre traffic to turn left on a flashing yellow arrow. Now, drivers can only turn left on a green arrow. You still get a flashing yellow arrow for east and west traffic on 44^th at the signal. New signage on the mast pole reflects this change.

MORE: Read more traffic issues driving people crazy

This is a fairly unique traffic signal that I have seen at various intersections around metro Denver. It is called a 4-section left turn signal and here is how it works. The top light is a red arrow indicating you can’t turn left. Below that is a solid yellow arrow, treated the same as a solid yellow light warning you that the signal is changing to red and you should prepare to stop. Below that is a flashing yellow arrow, saying you can turn left when oncoming traffic and pedestrians are clear. On the bottom is a green arrow that allows for unimpeded left turns. During this phase, opposing traffic is stopped and the Don’t Walk pedestrian indication is illuminated to prevent conflicts with pedestrians.

This signal was upgraded three years ago as part of an intersection improvement project where the older span wire traffic signals were replaced with more secure mast arm mounted signals. JeffCo Public Works tells me many of these span wire signals are aging, require increased maintenance, and cannot reliably withstand Jefferson County’s heavy windstorms. New mast arm signals are built to current standards and are better suited to local environmental conditions.

JeffCo has been gradually upgrading its signal system to improve resiliency, operations, and safety through modern technology. I was told the older signals lack the ability to support coordinated “green waves” that allows drivers to keep going at a constant posted speed, reducing congestion, improving travel times, and lowering vehicle emissions.

The newer signal technology also enhances safety by extending signal phases, when needed, so motorists, bicyclists, or pedestrians can clear the intersection before the signal changes. New components also allow emergency responders to interface with the system, improving response times by enabling more efficient remote preemption of signals.

I was told if you came up on a signal problem like this again, you should wait for another light cycle to see if the lights reset and work correctly. If it still doesn’t work, treat it as a yellow arrow and proceed when safe to do so.

Denver7 Traffic Expert Jayson Luber says he has been covering Denver-metro traffic since Ben-Hur was driving a chariot. (We believe the actual number is over 25 years.) He's obsessed with letting viewers know what's happening on their drive and the best way to avoid the problems that spring up. Follow him on Facebook, Twitter or Instagram or listen to his award winning Driving You Crazy podcast on any podcast app including iTunes, iHeartRadio, Spotify, Podbean, or YouTube.