Roadway Lighting and Safety: Phase II – Monitoring Quality, Durability and Efficiency, November 2011

This Phase II project follows a previous project titled Strategies to Address Nighttime Crashes at Rural, Unsignalized Intersections. Based on the results of the previous study, the Iowa Highway Research Board (IHRB) indicated interest in pursuing further research to address the quality of lighting, rather than just the presence of light, with respect to safety. The research team supplemented the literature review from the previous study, specifically addressing lighting level in terms of measurement, the relationship between light levels and safety, and lamp durability and efficiency. The Center for Transportation Research and Education (CTRE) teamed with a national research leader in roadway lighting, Virginia Tech Transportation Institute (VTTI) to collect the data. An integral instrument to the data collection efforts was the creation of the Roadway Monitoring System (RMS). The RMS allowed the research team to collect lighting data and approach information for each rural intersection identified in the previous phase. After data cleanup, the final data set contained illuminance data for 101 lighted intersections (of 137 lighted intersections in the first study). Data analysis included a robust statistical analysis based on Bayesian techniques. Average illuminance, average glare, and average uniformity ratio values were used to classify quality of lighting at the intersections.

Roadway Lighting and Safety: Phase II – Monitoring Quality, Durability and Efficiency, November 2011

This Phase II project follows a previous project titled Strategies to Address Nighttime Crashes at Rural, Unsignalized Intersections. Based on the results of the previous study, the Iowa Highway Research Board (IHRB) indicated interest in pursuing further research to address the quality of lighting, rather than just the presence of light, with respect to safety. The research team supplemented the literature review from the previous study, specifically addressing lighting level in terms of measurement, the relationship between light levels and safety, and lamp durability and efficiency. The Center for Transportation Research and Education (CTRE) teamed with a national research leader in roadway lighting, Virginia Tech Transportation Institute (VTTI) to collect the data. An integral instrument to the data collection efforts was the creation of the Roadway Monitoring System (RMS). The RMS allowed the research team to collect lighting data and approach information for each rural intersection identified in the previous phase. After data cleanup, the final data set contained illuminance data for 101 lighted intersections (of 137 lighted intersections in the first study). Data analysis included a robust statistical analysis based on Bayesian techniques. Average illuminance, average glare, and average uniformity ratio values were used to classify quality of lighting at the intersections.

Blue Light, What Should I do? Red Light, 2002

The Iowa State Patrol appreciates your assistance and compliance with these guidelines and laws to ensure the safety of the public and Iowa law enforcement.

Evaluation of PCC Long-Term Durability Using Intermediate Sized Gravels to Optimize Mix Gradations, April 2010

With the implementation of the 2000 Q-MC specification, an incentive is provided to produce an optimized gradation to improve placement characteristics. Also, specifications for slip-formed barrier rail have changed to require an optimized gradation. Generally, these optimized gradations have been achieved by blending an intermediate aggregate with the coarse and fine aggregate. The demand for this intermediate aggregate has been satisfied by using crushed limestone chips developed from the crushing of the parent concrete stone. The availability, cost, and physical limitations of crushed limestone chips can be a concern. A viable option in addressing these concerns is the use of gravel as the intermediate aggregate. Unfortunately, gravels of Class 3I durability are limited to a small geographic area in Mississippi river sands north of the Rock River. Class 3 or Class 2 durability gravels are more widely available across the state. The durability classification of gravels is based on the amount and quality of the carbonate fraction of the material. At present, no service histories or research exists to assess the impact of using Class 3 or 2 durability gravels would have on the long-term durability of Portland cement concrete (PCC) pavement requiring Class 3I aggregate.

Evaluation of Fly Ash Concrete Durability Containing Class II Durability Aggregates, July 1986

Fly ash was used in this evaluation study to replace 15% of the cement in Class C-3 concrete paving mixes. One Class "c" ash from Iowa approved sources was examined in each mix. Substitution rate was based on 1 to 1 basis, for each pound of cement removed 1.0 pound of ash was added. The freeze/thaw durability of the concrete studied was not adversely affected by the presence of fly ash. This study reveals that the durability of the concrete test specimens made with Class II durability aggregates was slightly increased in all cases by the substitution of cement with 15% Class "c" fly ash. In all cases durability factors either remained the same or slightly improved except for one case where the durability factor decreased from 36 to 34. The expansion decreased in all cases.

Evaluating the Effectiveness of Red Light Running Camera Enforcement in Cedar Rapids and Developing Guidelines For Selection and use of Red Light Running Countermeasures, Midwest Transportation Consortium, Final Report November 2011.

Red light running (RLR) is a problem in the US that has resulted in 165,000 injuries and 907 fatalities annually. In Iowa, RLR-related crashes make up 24.5 percent of all crashes and account for 31.7 percent of fatal and major injury crashes at signalized intersections. RLR crashes are a safety concern due to the increased likelihood of injury compared to other types of crashes. One tool used to combat red light running is automated enforcement in the form of RLR cameras. Automated enforcement, while effective, is often controversial. Cedar Rapids, Iowa installed RLR and speeding cameras at seven intersections across the city. The intersections were chosen based on crash rates and whether cameras could feasibly be placed at the intersection approaches. The cameras were placed starting in February 2010 with the last one becoming operational in December 2010. An analysis of the effect of the cameras on safety at these intersections was determined prudent in helping to justify the installation and effectiveness of the cameras. The objective of this research was to assess the safety effectiveness of the RLR program that has been implemented in Cedar Rapids. This was accomplished by analyzing data to determine changes in the following metrics:  Reductions in red light violation rates based on overall changes, time of day changes, and changes by lane  Effectiveness of the cameras over time  Time in which those running the red light enter the intersection  Changes in the average headway between vehicles entering the intersection

Evaluation of Fly Ash Concrete Durability Containing Class II Durability Aggregates, July 1986

Fly ash was used in this evaluation study to replace 15% of the cement in Class C-3 concrete paving mixes. One Class "c" ash from Iowa approved sources was examined in each mix. Substitution rate was based on 1 to 1 basis, for each pound of cement removed 1.0 pound of ash was added. The freeze/thaw durability of the concrete studied was not adversely affected by the presence of fly ash. This study reveals that the durability of the concrete test specimens made with Class II durability aggregates was slightly increased in all cases by the substitution of cement with 15% Class "c" fly ash. In all cases durability factors either remained the same or slightly improved except for one case where the durability factor decreased from 36 to 34. The expansion decreased in all cases.

Evaluating the Effectiveness of Red Light Running Camera Enforcement in Cedar Rapids and Developing Guidelines for Selection and Use of Red Light Running Countermeasures Final Report, November 2011

Red light running (RLR) is a problem in the US that has resulted in 165,000 injuries and 907 fatalities annually. In Iowa, RLR-related crashes make up 24.5 percent of all crashes and account for 31.7 percent of fatal and major injury crashes at signalized intersections. RLR crashes are a safety concern due to the increased likelihood of injury compared to other types of crashes. One tool used to combat red light running is automated enforcement in the form of RLR cameras. Automated enforcement, while effective, is often controversial. Cedar Rapids, Iowa installed RLR and speeding cameras at seven intersections across the city. The intersections were chosen based on crash rates and whether cameras could feasibly be placed at the intersection approaches. The cameras were placed starting in February 2010 with the last one becoming operational in December 2010. An analysis of the effect of the cameras on safety at these intersections was determined prudent in helping to justify the installation and effectiveness of the cameras. The objective of this research was to assess the safety effectiveness of the RLR program that has been implemented in Cedar Rapids. This was accomplished by analyzing data to determine changes in the following metrics:  Reductions in red light violation rates based on overall changes, time of day changes, and changes by lane  Effectiveness of the cameras over time  Time in which those running the red light enter the intersection  Changes in the average headway between vehicles entering the intersection

Toolbox of Countermeasures to Reduce Red Light Running Final Report, April 2012

Red light running (RLR) is a problem in the US that has resulted in 165,000 injuries and 907 fatalities annually. In Iowa, RLR-related crashes make up 24.5 percent of all crashes and account for 31.7 percent of fatal and major injury crashes at signalized intersections. RLR crashes are a safety concern due to the increased likelihood of injury compared to other types of crashes. The research team developed this toolbox for practitioners to address RLR crashes. The Four Es—Engineering, Enforcement, Education, and Emergency Response—should be used together to address RLR problems. However, this toolbox focuses on engineering, enforcement, and education solutions. The toolbox has two major parts:  Guidelines to identify problem intersections and the causes of RLR at intersections  Roadway-based and enforcement countermeasures for RLR

Red Light Running in Iowa, Jaunary 2001

Crashes related to red light running account for more than 800 deaths and thousands of injuries each year in the United States. Many states and local jurisdictions have undertaken studies and enacted programs in reaction to this major transportation safety concern. This research study examined the scope of this phenomenon in Iowa, reviewed red light running reduction studies and programs nationwide, and proposed countermeasures to address significant violation problems.

Report on a special investigation of the New Hampton Municipal Light Plant for the period January 1, 2001 through May 31, 2012

Report on a special investigation of the New Hampton Municipal Light Plant for the period January 1, 2001 through May 31, 2012

Report on a special investigation of the Coggon Municipal Light Plant for the period July 1, 2004 through August 27, 2012

Report on a special investigation of the Coggon Municipal Light Plant for the period July 1, 2004 through August 27, 2012

Long-Life Concrete: How Long Will My Concrete Last? A Synthesis of Knowledge of Potential Durability of Concrete, TPF-5(159), 2013

There is an ongoing discussion about moving toward performance-based specifications for concrete pavements. This document seeks to move the discussion forward by outlining the needs and the challenges, and proposing some immediate actions. However, this approach may increase risk for all parties until performance requirements are agreed upon and, more importantly, how the requirements can be measured. A fundamental issue behind pavement construction activities is that the owner/designer needs to be assured that the concrete in place will survive for the intended period (assuming there are no changes in the environment or loading) and, therefore, that full payment should be made. At the same time, each party along the supply chain needs to be assured that the material being supplied to them is able to meet the required performance, as is the product/system they are delivering. The focus of this document is a discussion of the issues behind this need, and the technologies that are available, or still needed, to meet this need, particularly from the point of view of potential durability

A Study of the Relative Durability and Drying Shrinkage of Concrete using Various Retarders, R-234, 1971

A number of concrete admixtures are presently used in various concretes principally for water reduction, retardation, or air entrainment. Whereas the use of these admixtures in concrete placement is well documented, there is limited information showing their effects on durability and drying shrinkage. Since the durability and the shrinkage of concrete can have a pronounce effect on a structures longevity, wear characteristics, and reaction to loading, it is desirable to know the relative effects of different admixtures prior to concrete placement. The purpose of this study is to provide information which could be used to establish durability and shrinkage criterion for evaluating the admixtures currently in use and those whose use may be proposed.

Fly Ash Concrete Compressive Strength and Freeze-Thaw Durability, MLR-81-06, 1981

The current study investigated the effect of fly ash class, source and amount on the compressive strength and freeze-thaw durability of fly ash concrete. Concrete aggregates of varying quality were also included as test variables. The current results and those obtained from previous laboratory and field work indicate that compressive strength can·be affected by fly ash class, source and amount while aggregate quality is shown to have no effect on strength. Freeze-thaw durability of fly ash concrete is strongly affected by aggregate quality and to a lesser degree by fly ash class, amount and source.