Ground has finally been broken and construction is slated to begin in earnest this week on the massive Central 70 project, which the Colorado Department of Transportation expects to take four to five years to complete.
This imprecision is likely to worry the many thousands of commuters who use the ten-mile stretch between the mousetrap where I-70 and I-25 meet and Chambers Road, and that's understandable. Undertakings this huge tend to take longer (and cost more money) than originally estimated.
Even CDOT acknowledges that its predictions involve some guesswork. The department's timeline, one of several images on view below, links the year 2022 with the phrase "Substantial Completion," which provides a high degree of wiggle room. After all, being 51 percent finished by then might qualify under that definition. And in smaller print beneath these words is an acknowledgement that the estimates are "Subject to Change."
With that in mind, here's what CDOT says is on the agenda during the next few months and over the course of several years thereafter, as well its list of things officials believe the Central 70 project "will" and "will not" do.
The assorted statements will be good to keep in mind if the interstate is still torn up come 2024.
This summer, CDOT says third-party partners will get to work on ten miles' worth of utility relocations, including Xcel power transmission, several long-haul fibers and what's termed CenturyLink's "backbone."
Additionally, Kiewit Meridiam Partners, the firm chosen to design, build, finance, operate and maintain the Central 70 project, will be tasked with relocating twenty miles of storm sewer, moving it from eighteen inches deep to 120 inches, or ten feet.
Also headed lower are three miles of sanitary sewer. Some of it will go from eight inches to thirty inches underground; other sections currently at a ten-foot depth will wind up thirty feet below the surface.
On top of that, there will be multiple utility relocations, including water and sewer, on the south side of 46th Avenue and environmental soil testing at approximately 2,000 locations; they're not specified.
Closures? There'll be a full shutdown of 46th Avenue between Brighton Boulevard and York Street and the construction of a railroad detour known as a "shoo-fly" on either side of the Union Pacific Railroad crossing over 46th between Brighton and York.
In addition, expect to see "clearing and grubbing" — the removal of shrubs, trees and prairie dogs, plus the installation of stormwater protection.
Business access is supposed to be maintained at all times through this process, though it could shift "as needed," CDOT acknowledges. Noise and dust reduction measures will also be put in place, with ongoing monitoring intended to ensure that the situation doesn't deteriorate.
Message boards and signage will update drivers on traffic impacts, CDOT pledges. Expect reduced speed limits through work zones.
Longer-term goals are depicted graphically in the following timeline.
As you can see, first phases in the areas on the west and east ends of the project are expected to get under way this year: bridges near 46th in the former, plus the I-270 connector bridge and outside lane widening in the latter.
Phase one of the west area is expected to last until the middle of 2020, while the east area's I-270 connector bridge should be done next year. The east side's lane widening, meanwhile, could be wrapped before the end of 2018.
If all goes well, everything in the east area will be completed before 2020 — about the same time work on the central area is slated to get under way. The four central phases, dealing with Stapleton Drive north and south, outside and inside work on the interstate itself and improvements to three cross streets — Dahlia, Holly and Monaco — have a finish projected for 2021.
Not so the west area, where the most complex work will take place. Between Brighton and Colorado boulevards, the road will be lowered approximately thirty feet below ground, and a four-acre cover that's about 1,000 feet from end to end will be built over a portion of it. The existing viaduct in this area is marked for removal in 2020, but the four west phases will continue to roll through the entirety of 2022.
While all of this is going on, CDOT promises that three lanes will be open in each direction during the daytime hours on weekdays and single-lane closures will be permitted at night only.
The department acknowledges that there will be a "very limited number" of full closures allowed on evenings and weekends, and "limited north/south closures."
For example, CDOT says, Clayton Street won't be closed at the same time as Columbine or Fillmore.
Residents and commuters will be given two weeks' notice for full road closures and detours expected to last seven days or longer, a week's notice for "major project activities" lasting less than seven days and a 24-hour heads-up for cancellations of planned closures or major traffic shifts.
More information can be found on CDOT's Central 70 page, which also includes a link to sign up for construction updates.
Continue to see the department bullet points about what the project will and won't do.
CDOT Says Central 70 Will....
• Provide the first safety and capacity improvements to I-70 since the highway's construction in 1964
• Provide one new Express Lane in each direction
• Provide auxiliary lanes for safe exiting and entering the highway
• Add eight-foot outside and twelve-foot inside shoulders for accidents and breakdowns
• Rebuild some existing side streets
• Permanently address the 54-year old viaduct, the second-largest bridge in Colorado and the last of the thirty worst bridges in the state yet to be addressed
• Add new capacity and choice with Express Lanes that encourage carpooling, accommodate future transit growth and guarantee drivers a congestion-free trip even as Colorado grows
• Create a vibrant and active four-acre park maintained by the City and County of Denver and modeled on other active spaces around the nation
• Ensure all aspects of the highway, including landscaping and snow removal, are maintained via strict standards placed on Kiewitt Meridiam Partners (KMP)
• Enhance pedestrian and bicycle connectivity and safety throughout the corridor by incorporating eight-foot sidewalks, tree lawns and lighting along roads
• Relieve congestion and create a functioning highway that makes it possible for drivers to use I-70 as a thoroughfare instead of the local street network
• Accommodate freight traffic on one of Colorado's most active industrial and commercial corridors, currently serving 1,200 businesses and 22,000 employees
• Provide a series of unprecedented mitigations, including a $2 million contribution to affordable housing development, funding for fresh food access, improvements to Swansea Elementary School and home improvements for nearly 300 homes
• Meet all health-based air-quality standards, which will result in emission levels that are equivalent or reduced compared to today, even with the nearly 50 percent increase in population and increased traffic expected by 2035
• Improve air quality in the area, including at Swansea Elementary School, by reducing congestion and building a lowered and partially covered highway
• Provide the residents and owners of 56 homes acquires for the project with full benefits under the Uniform Act, including covering the cost difference caused by market conditions
CDOT Says Central 70 Will Not....
• Add unnecessary or excessive lanes. The planned eight- to ten-lane template is similar to other major interstates in the metro area and is designed to safely carry more than 200,000 vehicles per day
• Prevent CDOT from addressing poor and structurally deficient bridges around the state. The Transportation Commission requires that no more than 50 percent of revenues from the Bridge Enterprise program be allocated to the Central 70 project
• Add new capacity as general purpose lanes where congestion can't be managed
• Further divide the Globeville, Elyria and Swansea neighborhoods
• Be subject to unknown funding sources for maintenance
• Reduce pedestrian and bicycle connectivity and safety
• Shift traffic to the local street network
• Shift freight traffic from the interstate to local streets
• Ignore the impacts to the community
• Cause violations of health-based air-quality standards set by the Environmental Protection Agency (EPA)
• Negatively impact long-term air quality
• Require residents displaced by the project to make up the difference between the value of their home and a new property with like characteristics or place restrictions on where residents choose to move