New, longer southbound ramps at Cimarron/I-25 will get enhancements later
This was how Don Garcia of Wilson and Company, a project consultant to the Colorado Department of Transportation (CDOT), summarized results of the new alignments that opened the weekend of May 14-15.
Following a schedule in which each element of the $113 million interchange replacement project leads into the next, the southbound off-ramp opened on the 14th and the on-ramp on the 15th.
“I was out here both nights, and people were driving it pretty good, like they knew where they were going,” Garcia said. He was aware of only one person who got mixed up, “and we don't know how that happened,” he added.
The new alignments replace those created 56 years ago, when the interstate was built through Colorado Springs - including the Cimarron interchange and the extension of the street itself west to Eighth Street.
The most obvious change is the off-ramp, which used to go over Cimarron and loop around to a stoplight at the south side of the street. The new route runs straight down from the interstate to Cimarron's north side. Its quarter-mile length is approximately 1,000 feet longer than the 400 feet provided by the original loop layout. “It won't have the backups onto I-25 like the loop did,” Garcia noted.
In essence, the southbound on-ramp is the same as before - curving up to the interstate. But it too is designed to be considerably longer, just under a
The new southbound on-ramp also does not have the “goofy curve,” as Garcia put it, that motorists used to encounter just before they came onto the interstate. In the new ramp's interim set-up, drivers will find themselves paralleling the current interstate alignment for some distance, with concrete barricades between them, until about a quarter-mile before the Tejon exit.
The new Cimarron ramps are planned to accommodate peak traffic totals of 1,700 cars an hour (off-ramp) and 1,900 (on-ramp), Garcia said.
When built in 1960, the interchange itself was designed to handle up to 7,500 interstate cars a day, according to figures from that project. By contrast, current statistics show an average through the interchange of more than 9,000 in just one hour.
When the current replacement project is complete (late 2017 is the plan), both new ramps will keep their greater length, along with final-version enhancements, according to Garcia. These will be:
- Added lanes - Currently there is one lane at the start of the off-ramp, opening up to two lanes just before Cimarron (one for left turns, one for rights).
- New bridge over Fountain Creek for the SB off-ramp - Its current bridge at Cimarron is temporary and will be used elsewhere in the project. The permanent bridge is being built beside it, just to the east (closer to the interchange), Garcia pointed out.
- Integration into interchange traffic design - Both the off-ramp egress and the on-ramp access will be part of a traffic layout under the interchange called a single-point urban interface (SPUI). A local SPUI example can be found at Garden of the Gods Road/I-25 interchange.
- Cimarron Street changes - To be part of the SPUI, the on-ramp access will need to be moved to a point just west of the interchange, about 100 feet east of where it is now. Also affecting the access point will be Cimarron Street itself, which will use the street's new bridge over the creek and be realigned 200 feet south of its current line.
Most of the final on-ramp roadway has been built and is being used with the current version. Because of the changed access point, the portion that's unbuilt (about 25 percent of the total length) will need to be laid in through the area where the old southbound off-ramp loop was. But its remains need to be cleared away first. “There's a lot of work we need to do,” Garcia said.
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