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Driving You Crazy: Why don't on-ramp metering lights alternate?

Could it be safer to alternate the cars?
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Posted at 5:20 AM, Feb 09, 2017
and last updated 2017-02-09 07:21:37-05

Marjorie from Aurora writes, “What is driving you crazy? Why don't on-ramp metering lights alternate? When both lanes have the green light at the same time, it seems to always end up in a game of "chicken." Not only do you need to watch traffic so that you can merge safely, but then you also have to watch the bozo in the next on-ramp lane so he/she doesn't cut you off. Makes no sense to me.”  

I’ve been to other cities Marjorie where they alternate traffic on the ramps just like you say and it seems to me to work well. CDOT has been operating freeway entrance ramp signals since the early 1990s.

Stacia Sellers, CDOT Region 1 Communications Specialist tells me while some agencies around the nation operate ramp metering systems by staggering the release of vehicles, ramp meters in the Denver area have operated with both lanes releasing at the same time, beginning with the earliest installations over 30 years ago.

“Within that time, we have not found that this type of operation has a quantifiable negative impact on safety,” said Sellers.

Another big reason CDOT wants to leave the metering ramps the way they are is it would be very expensive to change it.

“Federal guidelines now require that ramp meter installations in which both lanes are not released simultaneously, be constructed with overhead signals, which would add approximately $50,000-$75,000 per site in upgrade costs,” Sellers said.

MORE: Read more traffic issues driving people crazy

When you multiply that much money by the 150 ramp metering sites in the Denver metro area that would require improvements, the cost is just too high.

“Modifications to the control system software and to the controllers, signal equipment, and wiring at more than for which no funding is identified at this time,” Sellers said.

So even though you have a good idea, drivers leaving the stop bar at the current metered lights will have to still determine between each other rather quickly which of the two will enter first. 

Denver7 traffic reporter Jayson Luber says he has been covering Denver-metro traffic since Ben-Hur was driving a chariot. (We believe the actual number is over 20 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 and Twitter or listen to his Driving You Crazy podcast.