BUILD Grant application

This project will reconstruct 4.0 miles of Manufacturing Drive and Bluff Boulevard, a main corridor within the micropolitan community of Clinton in Eastern Iowa, into complete streets that will widen the corridor, introduce a roundabout, separate sewer and sanitary lines and include the planting of green infrastructure to capture rainwater and filter stormwater.

The project will reduce runoff volume and improve water quality, improve signaling, add sidewalks and a bicycle route, add transit shelters and will include intersection modifications for this vital artery of rural Clinton, Iowa.

Benefit Cost Analysis

A Benefit-Cost Analysis was performed for this project. The proposed project will result in a total cost of $28,678,000 (2018), including pavement, drainage, earthwork, bridges, retaining walls, traffic signals, Right of Way, and bicycle paths. The total benefits to the project, including travel time savings and safety benefits, are estimated to be $51,713,000. This results in a Benefit Cost Ratio of 1.84. Further detail is presented here. All costs are in 2018 dollars.

Travel Time Savings: Using the current and future build and no-build synchro models, the projected travel-time savings is approximately 17 hours in 2020, and 27 hours in 2040. Assuming a benefit of $15.24 per person-hour, this results in a total benefit of $2,542,700.

Safety Benefits (Corridor): Converting the current facility to two lanes with a two-way left-turn lane results in approximately 36% reduction in crashes for the corridor. This results in a possible reduction in over 132 crashes in the first five years. Extrapolating those benefits over a 20-year period, this results in a total benefit of $47,120,000.

Safety Benefits (Major Intersections): The project includes modifications at two intersections; Bluff Blvd. and 7th Avenue South/Thorwaldson, and Manufacturing Drive and Valley West Drive. When investigating cost modification factors (CMF), using the CMF clearinghouse, factors shown typically have a “Quality” rating that coincides with the data. This provides the evaluator a level of confidence in the data as it’s used. Unfortunately, the available data on crash modification rates for similar types of improvements (minor realignments, and conversion to two-lane two-way left turn lane) does not have very high quality ratings (3 out of 5 stars). CMF’s range from 0.54 to 0.76. Therefore, for this analysis, it was assumed that the CMF for the intersection was the same for the corridor, or 0.64. This results in a possible reduction of an additional 22 crashes in the first five years. Extrapolating those benefits over a 20-year period, this results in a total benefit of $2,050,000.

 

Budget

Total cost of the entire project is estimated at $29 million, which includes engineering and property acquisition. Given the current budget status of $3 million local City funds and $3 million State Transfer funds, the City has a current budget shortfall of $22.7 million.