Commuters and travelers driving I-235 through downtown Des Moines, IA, this summer will see construction crews begin to tackle one of the last, and most difficult pieces of a six-year interstate road reconstruction project.
Now in its fifth year, and to date the largest highway project to be let in the state of Iowa, workers will widen the westbound section of I-235 through downtown Des Moines from two to four lanes in each direction.
With the ADT projected to climb from the current 120,000 vpd, to 150,000 vpd, the good news to all the intense construction is that the commuting and traveling public will see much smoother sailing through downtown Des Moines on this stretch of the I-235 corridor once the road is completed sometime in 2007. The bad news is that drivers will continue to face traffic back-ups this year and next along with added slow-downs caused by the construction.
Given that this year is the 50th anniversary of the interstate freeway system, Iowans and its travelers are not alone in suffering through major and challenging road reconstruction.
States throughout the nation are going through similar road improvements and construction congestion to repair and add capacity caused by the aging interstate system.
The approximately 3-mi. segment of I-235 through downtown Des Moines is a major piece of highway improvements along a continuous, 14-mi. stretch of the freeway in the Des Moines area now under going a complete reconstruction.
The immediate goals of the construction are “to improve safety, update the facility to current roadway design standards, reduce congestion and improve mobility,” William Lusher, Iowa Department of Transportation (DOT) project manager explained. “This project will replace 71 bridges and 14 miles of mainline pavement and add an additional lane in each direction.”
The final freeway configuration will feature “three lanes in each direction with a fourth in the downtown area where traffic volumes currently exceed 120,000 vpd. Major interchange configuration changes in some areas required large amounts of earth excavation,” Lusher added.
The Iowa DOT awarded the $429-million contract to five Iowa contractors.
Cramer & Associates, United Contractors Inc. and Jensen Construction Co. teamed together to take on a huge piece of the project. Reilly Construction Co. and Des Moines Asphalt & Paving picked up the other pieces of the road project.
Funding for the project will come from a 90 percent/10 percent split between the federal and state governments.
According to Iowa DOT documents, I-235 is the primary transportation corridor through the Des Moines metropolitan area. This 14 mi. (22.5 km) stretch of road carries significantly more traffic than any other corridor in the state and is a key factor to economic growth of the area.
Rapidly deteriorating pavement, low clearances of the numerous bridges, closely spaced interchanges, limited traffic lanes resulting in congested traffic and extremely outdated traffic capacity sparked the reconstruction, according to Iowa DOT officials.
Crash statistics on this stretch of I-235 also are higher than average.
And the average of 850 collisions per year through the length of the project zone continues to rise.
State officials are confident that the wider freeway and improved interchanges along the route will save lives and head off serious crashes.
Since construction started in the Des Moines area, the Iowa DOT has implemented several construction techniques that have never been used in the state.
It is the first project to use soil nail anchored retaining walls, stone columns to support earth embankment and a traffic management center to aid in traffic control during construction.
The project is on schedule and within budget. Since digging, erecting and paving operations started, the five contractors have demolished and constructed 57 of the 71 bridges along the corridor, paved just under 9 mi. of the road and reconstructed 14 of the 16 interchanges.
Major quantities include 2.2 million cu. yd. (1.8 million cu m) of road excavation, 292,000 tons (265,000 t) of HMA pavement, 634,000 sq. yd. (530,000 sq m) of PCC pavement, 18 million lbs. (8.2 million kg) of reinforcing steel, 35 million lbs. (15.7 million kg) of structural steel and 65 million cu. yd. (49.7 million cu m) of structural concrete.
Additionally, 165 homes, five apartment buildings and 14 commercial properties were removed to make room for the added lanes.
Fourteen mi. of road reconstruction, 71 bridges and 16 interchanges is a mammoth challenge to undertake and complete in six years. Contractors on the project estimate it will take a small army of workers and hundreds of pieces of heavy equipment to complete the job.
United Contractors from Johnston, IA, alone will have two dozen pieces of heavy equipment on site, said Mike Jeffries, vice president of United Contractors. United equipment put into action includes a Link-Belt 8028 crane and several American crawler cranes, several Cat excavators and one Komatsu excavator, Cat dozers and loaders, JLG and APE boomlifts and several varieties of breakers and crushers, Jeffries said.
United workers will erect five bridges under its contract. Just these five bridges will consume 7,000 cu. yd. (5,250 cu m) of concrete, 885,000 lbs. (420,000 kg) of reinforcement, 1.1 million lbs. (490,000 kg) of steel and 6,888 sq. yd. (5,900 sq m) of MSE walls.
Along with weekend and nighttime bridge removals, “six-day work weeks with most of the bridges having an approximately 10 week completion date has been challenging,” Jeffries remarked.
However, Jeffries added, “construction has been going well. There have been some wet periods in the spring that slowed progress; however, the schedule has been maintained despite the wet weather.”
More than 50 percent of the project has been completed to date. Seven mi. of I-235 west of downtown Des Moines are complete along with the interchanges.
Construction is continuing through this summer and fall on the 3-mi. (4.9 km) section of the highway east of downtown. This portion of the road is expected to be completed by 2007.
Along the approximately 3-mi. section of mainline I 235 pavement through downtown Des Moines, road crews removed concrete on the westbound portion of the freeway earlier this spring.
All westbound traffic was switched to the existing eastbound lanes of I-235. Still carrying two lanes of traffic each direction, both east and westbound traffic will continue to flow on the existing eastbound lanes, though slower than usual because of traffic funneling into a more narrow section of road pavement.
Once the westbound paving is completed, workers will switch four lanes of traffic onto the newly completed westbound lanes and begin removing materials and paving the four new eastbound lanes of this section of I-235.
Work began on the downtown portion of the mainline pavement of the project last fall, said Richard Cheoene, project superintendent of Cramer & Associates. Workers spent the fall and winter months performing preparatory work for the upcoming grading and paving operations.
During this time, road crews moved utility lines, constructed storm sewers and removed one overpass to make way for the current grading and paving operations, Cheoene said.
Mild weather during the winter kept workers busy.
“This January was the best January I’ve ever worked in,” Cheoene remarked. “The average temperature was 40 degrees.”
Even a brief cold spell did not slow road crews Cheoene added.
Along with the everyday challenges of a project of this size and scope, communication among the contractors is critical.
By now, Cheoene said, “Most of the contractors have been involved since the start of construction in 2001. So, everybody knows everyone pretty well. We also have weekly coordination meetings with the Iowa DOT,” to maintain communications and coordination.
“This project has truly been an outstanding example of teamwork and dedication,” Lusher added. “Weekly project coordination meetings involving all of the prime contractor and their subs played a key role in maintaining the schedule.”
Lusher admitted that the next two years of construction work to rebuild I-235 and expand the pavement from two to four lanes in each direction through downtown Des Moines is a challenging schedule.
“I think [the schedule] is ambitious but the contractor feels it is doable. But it is an ambitious schedule,” Lusher said.
Cheoene added that it is always a challenge and difficult construction when moving in hundreds of workers and pieces of heavy equipment in a very tight, constricted construction zone with 120,000 vehicles zooming by within feet of the road crews.
Construction phasing becomes a primary design piece in any construction, but especially in working around thousands of moving vehicles, Lusher said.
All work on this project should be substantially completed by the end of 2007.CEG