It sounds like a dinosaur that once roamed the earth millions of years ago. But in 21st Century Denver, T-REX is as large as the extinct lizard that shares its nickname, but more apropos to the needs of the state’s residents.
T-REX is short for the $1.6 billion Transportation Expansion project that began in Denver June 1, 2001. The summer of 2006 marks the end of this five-year endeavor.
According to Tom Howell, the project manger for Southeast Corridor Constructors, a Denver-based joint venture design-build contractor that is comprised of Kiewit Construction and Parsons Transportation Group, the project’s scope of work called for the addition of 19 mi. (31 km) of double-track light rail connecting to the existing system at Broadway in Denver and extending along the west side of Interstate 25 (I-25) to Lincoln Avenue in Douglas County, and in the median of I-225 from I-25 to Parker Road in Aurora, CO.
The project also called for the construction of 13 stations, 12 of which include park-and-rides; the addition of 34 new light rail vehicles to the Regional Transportation District’s (RTD’s) existing fleet; and building a new light rail maintenance facility in Englewood, CO.
The light rail transit line will connect to the Central Corridor line to provide service to downtown Denver; the new Central Platte Valley line to provide service for Invesco Field at Mile High stadium, Elitch Gardens, the Pepsi Center, and the Denver Union Terminal; and to the Southwest Corridor line that provides service to Denver’s southwest suburbs, Howell explained.
Howell said T-REX also will add one through lane in each direction from Parker Road in Aurora to I-25, for a total of three lanes in each direction.
It will also add two through lanes in each direction from I-225 to the C-370/E-470 interchange for a total of five lanes in each direction.
Howell noted that the project’s scope also called for the reconstruction of eight interchanges, including I-25/I-225; reconstruction and widening of numerous bridges; improved drainage; enhanced safety; improved ramps, shoulders and acceleration and deceleration lanes.
Elaborating, Howell said that highway reconstruction totals 17 mi. (27.4 km), of which 14 mi. (22.5 km) stretch from I-25 at the Lincoln Interchange on the south end of the project to Broadway on the north end of the project. The remaining 3 mi. is from the I-25/I-225 interchange, out on I-225 to Parker Road.
The project also included the replacement or construction of bridges along the I-25 corridor.
Howell said replacement bridges were constructed for Franklin, Steele Downing and Washington streets as well as Louisiana and Evans avenues and University Boulevard.
Replaced bridges on I-25 were at Logan and Emerson streets and Quincy Avenue.
On I-225, the northbound and southbound bridges over Cherry Creek were widened. Bridges on I-25 were widened at Colorado Boulevard, Belleview Avenue and Orchard, Arapahoe, Dry Creek and County Line roads.
The Highline Canal/Bike Path under I-25, south of Yale, was improved for pedestrians and bicyclists, he added.
Howell pointed out that plans called for the reconfiguration and reconstruction of I-25 to improve safety and to accommodate the addition of the light rail tracks and facilities.
Light rail bridges along I-25 and I-225 were built at I-225 at Cherry Creek, Colorado, University and DTC boulevards; Broadway, Yale and Evans, Belleview and Hampden avenues; Highline Canal/Bike Path; the I-25/I-225 interchange; C-470; and Orchard, Arapaho, Dry Canal and County Line, and Parker roads.
Among the project team’s challenges was minimizing the impact of the construction to traveling public.
“We had to maintain three lanes of traffic in two directions from 5:40 a.m. to 8 p.m. every day,” Howell noted.
To minimize the impact of the construction affecting 250,000 vehicles daily, “we worked closely with the owner to develop a manageable sequence of phases in which to perform all of the work. This required working with the 12 cities and municipalities along the project’s route,” he added.
Another project challenge was the drainage in an area known as the “narrows,” which is located between Broadway and University Boulevard.
Howell said this was a 3-mi. area of high flooding before the contract. The solution, Howell explained, was to bore a 13-ft. diameter tunnel from the narrows to the Platte River. This was done by Elmore, a San Diego, CA-based subcontractor that used a tunnel boring machine to perform the job.
The solution also included a box culvert storm sewer trunk main along the side of the highway. The existing storm sewer in I-225’s median was relocated to accommodate the light rail line.
The design-build method of construction also proved challenging, according to Howell.
To make it work required sequencing the project and engaging a team concept for project development as construction proceeded. The benefits of design-build for this project included the ability to fast-track the project, lower the cost of the project, and provide better coordination of all of the team’s players and third-party entities, he added.
Sequencing a project’s milestones on an endeavor this large also required a large number of workers.
“At our peak, we had 750 craft workers, 250 additional supervisors and engineers, 400 crew members working for our subcontractors, and 350 designers on the design team.” Howell pointed out.
Partnering was also a big part of this project, he noted. It involved a contractual agreement between RTD and the Colorado Department of Transportation (CDOT), who agreed to work together to finance and construct T-REX; the Federal Highway Administration (FHWA) and Federal Transit Administration (FTA), which jointly developed an inter-agency agreement that outlined the guiding principles and designated responsibilities for each of the agencies.
Partnering began as bi-monthly meetings at the executive level and, at the project level meeting, had the project management team divide the project into more than 20 task forces that each held their own partnering meetings that included the development of team goals, he added.
He added that CDOT and RTD jointly pursued federal and local funding for the project. Financing features include cost savings through accelerated construction using the design-build method of project delivery; bonding of future federal allocations; bonding through sales tax revenues, federal funds from the FTA, and local matching funds from various municipalities and jurisdictions.
He elaborated that the design-build contract is worth approximately $1.18 billion; the light rail component will cost $879 million, 40 percent of which will come from the RTD and local matching funds, and the balance coming from the FTA Full funding Grant Agreement. The highway component of the project will cost $795 million. It was funded with a combination of the Highway Users Tax Fund and Senate Bill 97-01 money, bonding and federal revenues.
T-REX also features an “Art-n-Transit” program to create art at the new stations to foster a connection between neighborhoods and transit, adding value to the transit system and community as a whole, he pointed out.
There were also right-of-way issues. While the right-of-ways for I-25 and I-225 are owned by RTD and CDOT, the widening of I-25 and the construction of light rail transit and related facilities required some right-of-way purchases, Howell said.
“Working with a $100 million budget, the T-REX project acquired six single-family homes, two duplexes and two apartment buildings. It negotiated a total of 30 acquisitions and 172 partial acquisitions. All residents and tenants were eligible for relocation assistance and compensation. This included help in finding comparable replacement housing, replacement housing costs, including money to supplement a home purchase, money to supplement rent, moving costs, and down payment assistance.”
Utilities within the right-of-ways had to be relocated to accommodate highway widening and construction of the light rail transit. This involved more than 600 locations throughout the corridor at a cost of $2.5 million. This work was done prior to Southeast Corridor Constructors was issued a “Notice to Proceed.”
To reduce inconvenience to the traveling public, new boring technologies were used that eliminated the need to relocate utilities by open cuts on the roads.
In addition, Howell said, Southeast Corridor Constructors developed a new lighting system for the project.
“The original lighting system designed for T-REX required 40-foot light poles with 400-watt lamps every 180 feet on both sides of I-25 and I-225,” he said. “This design required more than 1,500 light poles for the 17-mile highway portion of the project. The design uses 1,000-watt lamps mounted on 65-foot poles placed about every 370 feet in the highway median. This reduced the number of light poles required to about 250. In addition, since the poles are in the highway median they are from 68 feet to 80 feet further away from properties adjacent to the highways.”
On the environmental front, Howell explained that the project team worked closely with local, state and federal agencies to ensure that environmental impacts were minimized during construction.
Measures taken to ensure air quality included suppressing dust through watering and other methods, covering trucks hauling soil, covering and stabilizing stockpile areas, replanting exposed areas, washing construction equipment to minimize the tracking of debris from the various construction sites, and monitoring air quality during construction.
He said that measures taken to protect water quality included adhering to local and state erosion control requirements, treating contaminated trench water, avoiding impacts to wetlands and other habitats, developing storm water practices required for CDOT’s municipal storm water permit, and adhering to the U.S. Army Corps of Engineers’ limits regarding filling in wetlands and streams.
Measures taken by the project team to mitigate noise and vibration included building temporary noise barriers during construction where necessary, minimizing the length of construction in residential areas, minimizing night-time construction in residential areas, routing truck traffic away from residential streets, where possible, combining noisy operations to occur simultaneously, and performing high noise construction activities during the day, where possible.
According to Howell, CDOT also used noise walls along the roadways to mitigate noise from highway traffic. The noise walls were made of masonry or concrete panels and rose from 10 ft. to 16 ft. in height.
Quality control and management were also essential to the project. They served as driving forces behind a systematic approach to ensure that all of the work complied with government requirements, Howell said.
To succeed, Southeast Corridor Contractors devised a plan to provide a framework for quality assurance and management.
This plan, he added, was designed to meet the requirements of the ISO 9001:2000 standard; was designed in accordance with contract requirements and to satisfy the FTA’s quality control and quality assurance guidelines; and to meet the contract requirements of the T-REX “Construction Quality Management Plan.”
A “Quality System Manual,” which describes the plan, specifies the means to achieve quality in accordance with the project’s requirements.
To keep the public informed, Howell said, the T-REX team implemented a public outreach program that included presentations to service organizations, homeowners, associations, large employers, school groups and other concerned entities. It also included project newsletters distributed every two weeks, telephone call centers, booths at community events, a T-REX “info-van,” an interactive Web site, an aggressive media relations program, and a Hotline Information Reporting System, he added.
Howell said project accomplishments included reconstruction of the nation’s 14th busiest interchange and an improved traffic flow through the interchange that was the result of changing the left-hand on and off ramps to right-hand on and off ramps to improve safety.
Another accomplishment, he added, was changing the LRT from a flyover over the interchange to below the interchange to make maintenance easier for the owner and improve fire and life safety conditions.
Howell, proud of yet another accomplishment, noted that penalties for not making milestones in the contract for Southeast Corridor Constructors could not exceed $50 million. This served as an incentive to meet the schedule for each milestone. Finishing a milestone ahead of schedule also meant a savings in the cost of doing business.
“We had $115 million in change orders and still will bring the schedule on time and under budget,” Howell said, adding that the project will be completed Sept. 1, 2006.” CEG