Archive for Thursday, July 27, 2006

83rd Street upgrade provides sticker shock

Hopes to leverage Arbor Ridge’s required improvements may not be feasible

July 27, 2006

The De Soto City Council learned last week it wouldn't cost much more to improve 83rd Street to a three-lane street between Kill Creek and Waverly roads than it would to upgrade the section to a two-lane street with turn lanes. The problem is both options exceed $5 million.

The plans and estimates were provided to the council last Thursday by representatives of Phelps Engineering Inc. The council agreed to have the firm review improvements to the street as part of a package of those required of Lambie/Geer, the developer of the Arbor Ridge Subdivision.

The final plat of that subdivision requires the developer to install turn lanes on 83rd at Kill Creek Road and a future entry into the subdivision to be called Ingrid Street. Those improvements plus required a sidewalk on the south side of 83rd east of Kill Creek were estimated to cost $680,000.

Former City Administrator Greg Johnson and city engineer Mike Brungardt first proposed in July 2005 the city might consider leveraging those required improvements to make further upgrades to the 1/2-mile stretch of 83rd.

With that, the city asked Phelps Engineering Inc. to examine several improvement options.

In response, the firm's engineers developed preliminary plans for the two-lane with turn lanes and the three-lane upgrade options. Additionally, the engineers looked at the costs of placing a traffic-control roundabout at 83rd and Kill Creek and a traditional traffic light. Lambie/Geer must participate in a benefit district for future traffic control measures at the intersection.

Phelps engineer Judd Claussen said it was estimated the three-lane 44-foot-wide street improvement would cost an estimated $5.37 million while a 28-foot-wide street with turn lanes would cost $5.04 million.

The need in both options to replace existing drainage elements and to cut hills and fill in valleys accounted for the relatively narrow difference in cost estimates, Claussen said.

Depending on the street width chosen, a roundabout would cost an additional $52,800 or $55,700 more than a traditional traffic light, Claussen said. Roundabouts have been found to be safer and handle traffic faster than signals, he said.

There was a possibility one substantial cost element could be eliminated, Brungardt said.

The estimate included $481,000 for a retaining wall to stabilize excavation of a hillside just east of Valley Springs Drive. Brungardt said it was possible the underlying limestone could support the excavation without the wall.

As a next step, he received the council's authorization to drill for rock samples at the site to determine if the retaining wall was needed.

Brungardt said he would also study whether money could be saved by preserving some existing roadbed and eliminating boulevard-style lighting and a sidewalk on the north side of 83rd Street (suggestions the council endorsed).

When the plan and estimates were presented Tuesday to the De Soto Planning Commission, it was suggested curbs and guttering could be left out on the eastern sections of the street near Waverly Road.

But considerable outside funding would be needed to make the project feasible even with those adjustments, Brungardt acknowledged. Possible funding sources included the state, Mid-America Regional Council and Johnson County, he said.

The project would seem to meet the criteria needed to qualify for the Johnson County CARS program, Brungardt said. But even should it be approved for that funding source, it was unrealistic to assume the county would pick up the bulk of the project's expense, he said.

"A combination of funding sources is going to have to drive it," he said.

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