In-Pavement Pedestrian Flasher Evaluation: Cedar Rapids, Iowa, 2004

Numerous strategies have been experimented with nationwide in an attempt to reduce the overall number of pedestrian-vehicle crashes, especially in instances where improper crossing or failure to yield was the proximate cause of the crash. Some of these measures include overhead signs, flashing warning beacons, advanced crossing signs, more visible pavement markings, in-street “Yield to Pedestrian” signs, and more recently, in-pavement flashing lights. Pedestrian safety has been a key issue for the City of Cedar Rapids, Iowa, in particular at non-controlled intersections and mid-block crossings. In 2002, the city council gave preliminary approval to implement a pedestrian-actuated overhead flasher system in conjunction with an in-pavement flasher system at the intersection of 1st Avenue NE and 4th Street NE in the downtown central business district. This location is uncontrolled and has several elements that can create conflicts between pedestrians, vehicles, and trains that service local industry. This report summarizes the results from a small-scale study completed by CTRE to evaluate the effectiveness of the in-pavement flasher system installed in downtown Cedar Rapids. The installation of in-pavement flashing warning lights at the pedestrian crosswalk at this site has had a net positive effect on the safety characteristics of the location. The results of this study show a marked improvement in motorist compliance with the state law requiring that motorists yield to pedestrians in the crosswalk. The pedestrian and motorist surveys show that both groups felt the in-pavement flashing lights have increased motorist awareness, especially at night. The data indicate the in-pavement flashing warning lights improved the motorists' response to pedestrians in the area, and that the system could be operational throughout summer and winter conditions.

Watershed Planning Advisory Council 2015 Annual Report, December 10, 2015

The Watershed Planning Advisory Council (WPAC) was established by the Iowa Legislature (see Appendix A: Iowa Code 466B.31) to assemble a diverse group of stakeholders to make recommendations to state and federal agencies to protect water resources in Iowa. In 2015, WPAC prioritized the seven areas for recommendations outlined in 466B.31, and small work groups drafted recommendations for approval by the full membership.

The Use of Fly Ash in Highway Construction, HR-1031, Progress Report, 1986

In 1982 the Iowa DOT allowed a successful bidder the option of submitting materials and proportions using fly ash to produce a portland cement concrete (PCC) paving mixture to meet a specified compressive strength. The contractor, Irving F. Jensen, received approval for the use of a concrete mixture utilizing 500 lbs. of portland cement and 88 lbs. of fly ash as a replacement of 88 lbs. of portland cement. The PCC mixture was utilized on the Muscatine County US 61 relocation bypass paved as project F-61-4(32)--20-70. A Class "C" fly ash obtained from the Chillicothe electric generating plant approximately 100 miles away was used in the project. This use of fly ash in lieu of portland cement resulted in a cost savings of $64,500 and an energy savings of approximately 16 billion BTU. The compressive strength of this PCC mixture option was very comparable to concrete mixtures produced without the use of fly ash. The pavement has been performing very well. The substitution of fly ash for 15% of the cement has been allowed as a contractor's option since 1984. Due to the cost savings, it has been used in almost all Iowa PCC paving since that time.