Only four noise barriers are recommended for the proposed new six-lane Interstate 74 corridor, despite the identification of 11 locations where the increased traffic sounds are expected to exceed federal noise abatement criteria.
The noise impacts and recommended list of four projects are contained in the Final Environmental Impact Statement issued for the project last month.
Seven of the 11 noise abatement projects were not recommended because they were deemed "economically unjustified" based on the number of residences currently adjacent to the roadway.
The four noise barriers recommended for construction in the impact statement are:
• Southwest of the Middle Road, Iowa, interchange adjacent to two apartment buildings. The 14-foot barrier would be 1,806 feet long and cost an estimated $110,000.
• East of I-74 and north of Lincoln Road, Iowa, adjacent to an apartment complex. The 8- to 16-foot barrier would be 500 feet long and cost an estimated $204,000.
• West of I-74 and south of River Drive, Moline. The 6- to 14-foot barrier would be 1,355 feet long and cost an estimated $518,000.
• Northwest of the Avenue of the Cities, Moline, interchange. The 10-foot barrier would be 617 feet long and cost an estimated $185,000.
The $1 million for noise abatement structures amounts to a tenth of 1 percent of the estimated $1 billion cost of the overall bridge and corridor project. More than $18 million spent has been spent to date on the project's environmental impact statement and preliminary bridge/corridor designs.
Constructing all 11 noise abatement barriers at all the sites where noise levels will exceed federal noise standards would cost an estimated $5 million.
