Preston, Howard

MnDOT is attempting to address an information gap by conducting a comprehensive and systematic analysis of economic effects of a highway improvement project—the conversion of US 12 to Interstate 394 (I-394). This I-394 Business Impact Study is a first step in documenting credible, local information about the potential business related impacts associated with highway improvements. This research is intended to provide a comprehensive long-term evaluation of the transportation, business, and land development impacts of a major transportation project in the Minneapolis-St. Paul metropolitan area.

This study was conducted to develop a rational method for selecting the most appropriate type of traffic control at construction sites involving the closing of a one-lane bridge. The study consisted of a literature review, a survey of practices in other states, the observation of a number of actual construction sites, the collection and analysis of data from these construction sites and finally, the development of methods for estimating the capacity and measuring the effectiveness of various types of traffic control. As a result, a method for selecting an appropriate type of traffic was developed. This method takes into account variables such as sight distance, bridge length, traffic volumes and capacity, consideration of the costs and benefits of various types of control and an analysis of the geometric features of the geometric features of the approaches to the bridge.

This research report focuses on the access management initiative and provides an overview of the following issues: • Definition of Access Management • Statutory Authority • Previous Research • Issue Discussion • Case Studies • Guidelines • Potential Topics for Further Research Using the concept of functional classification can assist in setting priorities for the application of access management initiatives. The application of access management strategies has resulted in statistically significant reductions in crashes on a wide variety of rural and urban roads. However, the data indicates that the greatest opportunities for crash reductions are on urban arterials, due to the typically higher crash frequencies, higher access densities, and higher levels of turning traffic found on these types of roadways. The development, adoption, and deployment of access management strategies should be a high priority for all road authorities because it appears that such action would benefit all classifications of roadways. A comprehensive set of access management guidelines should include both a traffic-engineering element with a toolbox of mitigation strategies for dealing with existing roadway deficiencies and a land-planning element to deal with future issues.

The primary objective of this report is to present statistically reliable conclusions relative to the changes in crash frequencies and other crash characteristics at isolated rural intersections associated with the installation of street lighting. It was found through a comparative analysis of over 3,400 rural intersections and a Before versus After analysis of a sample of 12 intersections that the installation of street lighting reduced both nighttime crash frequencies (25% to 40%) and crash severity (8% to 26%). A Benefit – Cost analysis using statistics from the Before versus After analysis found that crash reduction benefits associated with the installation of street lighting at rural intersections outweigh the costs by a wide margin. As a result of the analysis, it was concluded that the installation of street lighting at rural intersections is a low cost and very effective strategy for mitigating nighttime crashes. This strategy should be added to the traffic engineer’s toolbox and agencies should be encouraged to increase the use of streetlights at rural intersections in order to reduce crashes and improve motorist guidance. It was also concluded based on a comparison to the results for other recent research that the use of street lighting to reduce nighttime crashes at rural intersections would likely be far more effective than either rumble strips or flashing overhead beacons.

To fully apprize the Legislature of the potential impacts of access management, the Minnesota Department of Transportation (Mn/DOT) has gathered information and conducted research in order to make recommendations covering a wide range of interrelated land use planning, engineering, and legal practices to maximize the operational efficiency and safety of all functional categories of roadways. The study focused on first identifying and then analyzing a random and statistically representative sample of roadways. The following highlights some of the study’s conclusions:  There is an observed positive relationship between access density and crash rates in 10 of 11 highway categories.  Additional analysis of the crash data in each of the categories revealed that in all cases, roadway segments with the highest crash rates have high levels of access density and segments with the lowest crash rates have low levels of access density.  A review of case studies of 11 access management-related projects (three in Minnesota and eight in Iowa) documented an average crash reduction of approximately 40 percent.  A benefit-cost analysis was completed for the 11 roadway categories. The results are based on a range of estimated project costs and crash reductions and indicate that positive outcomes are possible in every category.  Crash data was analyzed from two different perspectives; a comparison of crash rates on a random sample of the state's highway system and a before/after comparison of crash rates from 11 case studies. The results from each approach suggest a strong and statistically sound relationship between levels of accessibility and crash rates.  The final conclusion addresses the question: Is access management a legitimate public safety issue? All results of the various analyses suggest that yes; access management is a legitimate public safety issue.

The 10-Year Analysis of Sample MnDOT Research Projects is a spreadsheet tool that pertains to report 2017-13, Development of a Process for Quantifying the Benefits of Research.

The 3-Year Analysis of Sample MnDOT Research Projects is a spreadsheet tool that pertains to report 2017-13, Development of a Process for Quantifying the Benefits of Research.

This PowerPoint presentation was created as a part of Research Report 2017-13, "Development of a Process for Quantifying the Benefits of Research."

This Benefits Quantification Tool was created as part of Research Report 2017-13, "Development of a Process for Quantifying the Benefits of Research." The tool consists of six templates with built in formulas that can be used for calculating the potential benefits of a project. The different templates can be used based on what category of benefit the project provides.

The purpose of this user guide is to explain the seven-step benefit quantification process and use of Research Services’ benefit quantification spreadsheet tool. It pertains to Report 2017-13, Development of a Process for Quantifying the Benefits of Research.