If Colorado Springs residents needed another sign that traffic in their city is becoming more like Denver, it’ll soon be visible at the end of on-ramps to Interstate 25.
The Colorado Department of Transportation will begin installing ramp meters — traffic lights that allow one car at time to merge onto the interstate — at on-ramps from Rockrimmon Boulevard to Nevada Avenue south of downtown this summer, said CDOT spokeswoman Michelle Peulen.
The traffic lights, which will be at the end of the on-ramps when the project is completed next year, reduce congestion by allowing vehicles onto I-25 at a steady pace, Peulen said.
The lights will be equipped with sensors so that they are activated when vehicle speeds on I-25 fall to 45 mph or below. The lights will be red for a few seconds at a time and allow one car to enter the interstate each time they turn green, Peulen said.
The project marks the first time that ramp metering, now commonplace on busy highways in the Denver area, will be used in southeastern Colorado.
“I think the public is going to be pleasantly surprised when they see the difference that they make and the improved operations of the I-25 corridor through that area,” Peulen said.
The Denver area is home to about 120 active ramp metering sites at gateways to thoroughfares including I-25, I-70, C-470 and I-225, said CDOT traffic operations engineer Ben Kiene. Plans call for more on I-76, C-470, and I-25 north of Castle Rock, he said.
State transportation officials have found that the ramps help increase the amount of traffic that highways can handle and reduce rear-end crashes, Kiene said.
After ramp meters were installed on a stretch of southbound I-25 in Denver, average vehicle speed increased 31 percent, or 8.6 mph, according to CDOT’s website. A section of C-470 saw speeds rise an average of 10%, or 7 mph, after the devices were added to on-ramps, the website states.
In the Denver area, the lights usually remain red for 2 to 12 seconds, depending on traffic, Kiene said.
CDOT installed its first ramp meters in Denver in 1984, Kiene said. They’ve become more “well-established” since then, and now only generate sporadic complaints from commuters, he said.
For local governments across the country, ramp metering is becoming a more widely used solution to improve traffic flow at a relatively low cost, he said.
“As transportation funding is more scarce, it’s often not practical to add physical capacity to a freeway,” Kiene said. “So the intent of the ramp metering is to try to squeeze more capacity out of what you already have.”
The meters will be installed on the northbound and southbound on-ramps at Garden of the Gods Road, Fillmore Street, Fontanero Street and Uintah Street. They will also be added to northbound ramps at Bijou Street and Nevada Avenue and the southbound ramp at Rockrimmon Boulevard.
Installing the meters in Colorado Springs will involve erecting poles equipped with signals and control boxes and placing other hardware, such as sensors and communication devices. Conduit will also need to be buried, Peulen said.
She said she expects that most of the work will be done at night beginning in July or August.
After the ramp-meter installation is completed next spring, CDOT will likely turn on the signals one at a time to test them, Peulen said.