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With interest in collision avoidance technology for highway vehicles on the rise, this report presents an overview of current collision avoidance technology, the technical work required to bring these systems to a commercially viable product, and the societal issues that need addressing before wide-scale deployment can occur. Many questions remain about the benefits of deploying such systems, the costs, the effect of these systems on drivers, and the steps necessary to effectively regulate vehicles equipped with such systems. In addition to technical aspects, the report also discusses the issues that society will face during development and deployment of these systems, which may prove bigger impediments to deployment than technical issues. The report also recommends a research plan to perform fair, unbiased evaluations of emerging collision avoidance technology.

This project involved investigating the effect, if any, of rumble strips on stopping behavior at simulated rural-controlled intersections. Researchers used the wrap-around driver simulator at the University of Minnesota's Human Factors Research Laboratory for the project. Researchers varied the rumble strip type and the number of rumble strips and tested them on two different types of controlled intersections, two-way or four-way, and in the presence and absence of traffic. Results indicate that none of these manipulations seem to affect the point at which drivers stop at the controlled intersections or the point at which drivers start to slow down at controlled intersections. The research did reveal drivers brake more, earlier, when rumble strips are installed than they do if there are no rumble strips. Although they started to slow down at the same time and finished braking at the same time, there was more use of the brake earlier in the slowing down maneuver in the presence of rumble strips. Results also reveal that drivers brake more and earlier with full coverage rumble strips than they do with wheel track rumble strips.

This study analyzed the relationship between the size of the forward looking blindspot (FLB) produced by vehicles A-post (windshield frame), the speeds of two vehicles approaching an intersection at right angles, and driver behavior relative to a likely accident event. Researchers observed 28 volunteer participants directly and by four channels of on-board video cameras while they drove in a simulator at the Human Factors Research Laboratory. They noted the way that participants scanned the virtual environment and scored at four levels of scanning activity. They also tracked visual acquisition of the target vehicle and incidence of collision. Only 6.3% of the total fell into type one scanning (eyes fixed). Type II (eyes only) accounted for the highest incident rate at almost 44%. The study considered both as "inactive" forms of scanning. Target vehicle acquisition rate increased with the activity level of the scanning type. The target acquisition rate increased significantly from scanning level one to level two and from scanning level two to level three. There was not a significant increase in the acquisition rate from scanning level three to level four. Not surprisingly, collision rates decreased with increases in scanning level. Collision rates significantly dropped between scanning levels two and three and scanning levels three and four. Yield signs at intersections produced no significant correlation with acquisition rate, collision rate, or scanning level.

This research explores the potential safety effects of dynamic signing at rural horizontal curves. It accomplishes this by asking two key questions. First, is there a relationship between a vehicle's speed on the approach to a curve and the ability to successfully navigate the curve? Second, is there a difference between static and dynamic signing in the ability to reduce the speed of high-speed vehicles? Researchers assembled an off-the-shelf hardware and software package and deployed it at a four-degree curve along CSAH 54 in rural Dakota County. If purchased new, the package would cost about $50,000; however, an agency could deploy the components necessary to perform dynamic curve warning (a changeable message sign and radar unit) for approximately $10,000. The field test collected vehicle speed data for about 2,600 vehicles. In addition, researchers tracked and videotaped 600 vehicles. The data suggest, and statistical tests confirm, that the initial speed of a vehicle before entering a curve does have a statistically significant effect on the probability of successfully navigating through the curve. The data also indicated that the overall effect of the dynamic curve warning system on vehicle speeds is relatively small. However, the dynamic system had a much greater effect on high-speed vehicles than the static curve warning sign and the dynamic system significantly improved the ability of the high-speed vehicles to successfully navigate through the curve.

A driving simulation experiment was conducted to research interventions to right-angle crashes at rural Thru-STOP intersections, which accounted for 71% of Minnesota fatal crashes in 1998, 1999, and the first half of 2000. The interventions caused drivers to reduce speed as they neared the intersection, and implies that 1) drivers are less likely to inadvertently run stop signs when slowing down further from the intersection, 2) making the intersection more noticeable improves driver safety judgment, and 3) speed reductions on the major road of an intersection produce greater reductions in stopping distances.

This study presents statistically reliable conclusions based on a comparison of the operational and safety characteristics of rural intersections without turning lanes, with bypass lanes, and with left turn lanes. The basic work tasks associated with the research study included: a literature search of nationally published research reports, a survey of bypass lane use, a summary of the legal issues associated with passing on the right, operations and safety analyses, and a review of Minnesota Department of Transportation (Mn/DOT) recommended design guidelines and design features. The results of the safety and operations analyses did not offer a high degree of statistical reliability. However, a comparative crash analysis and a before-versus-after analysis suggested that it is impossible to conclude that the use of a bypass lane provides a greater degree of safety, and, therefore, bypass lanes should not be used as a safety device. There also were some concerns expressed about safety issues at four-legged intersections. Recommendations included: Revise Mn/DOT turn lane policies to at least reduce or eliminate the use of bypass lanes at four-legged intersections; Consider developing a shorter and less costly exclusive left turn lane design; and Offer designers positive guidance regarding the use of left-turn lanes, through a prioritized approach based on the functional classification of the major roadway.

Currently, many townships, cities and some rural counties do not have entrance policies and design standards. This report provides rationale on why access should be managed in rural areas. It also identifies fundamental planning principles, design guidelines and best management practices for lower-volume rural roadways. Additional information sources for developing or refining local policies are included. The study reviewed literature, conducted a survey of rural Minnesota counties, townships and cities and identified the following best management practices (BMPs): (1) Establish a formal access policy to determine the need and evaluate use, location and design of requested access points; (2) Encourage coordination during the zoning and platting process; (3) Adopt a policy that grants access for a specific use. If this use should change, a new access permit would be required; (4) Encourage adequate spacing of access points; (5) Protect the functional area of intersections in order to separate conflict areas (typically 480 to 820 feet from the intersection); (6) Ensure adequate sight distance at entrances; (7) Avoid offset or "dogleg" intersections and entrances; (8) Encourage turn lanes and bypass lanes (on higher speed roadways); (9) Consider providing shared access or relocating existing access; and (10) Encourage good driveway and intersection design characteristics.

In this study, we examine population and housing change, changes in industrial activity and occupational changes, and characteristics of commuters and the journey to work for those working away from home in 26 regional centers and their commute sheds in Greater Minnesota. We also explore ways in which Public Use Microdata Samples (PUMS) and Public Use Microdata Areas (PUMAs) might be exploited to shed additional insight into the changing nature of the demographic, economic and commuting patterns that are now pervasive throughout Greater Minnesota. These data are evaluated to explore links between demographic and economic features of working-age populations, and relationships between worker and household characteristics and aspects of commuting activity on the other. The final chapter examines regional economic vitality and travel behavior across the Minnesota Countryside. When population change in sample regional centers in the 1990s is compared with change in the nearby counties that comprise the centers' commuting fields, four situations appear: those where centers and their commuting fields both had population increases; centers with declining populations, but increases in the commuting fields; centers with growing populations, but with declines in their commuting fields; and situations where both the center and the commute field lost population.

Deployment of any system is driven by market demand and system cost. Initial deployment of the Intelligent Vehicle Lab Snowplow Driver Assistive System (DAS) was limited to a 45 mile section of Minnesota Trunk Highway 7 west of I-494 and east of Hutchinson MN. To better gage demand and functionality, St. Louis and Polk Counties in Minnesota operationally tested the system during the winter of 2003-2004; Polk County also tested during the winter of 2004-2005. Operational benefits were found to be drastically different in the two counties. Low visibility was not an issue with the St. Louis County snowplow routes, so the system offered few benefits. In contrast the topology of Polk county is flat, with almost no trees. High winds combined with few visual cues create significant low visibility conditions. Polk County was pleased with their original system, and obtained a second system and tested it operationally during the 2004-2005 winter. The experience of these two counties is documented in this volume, Volume One. A key component of the DAS is a high accuracy digital map. With the exception of the mapping process, the present cost of the DAS is well documented. Volume Two describes a system designed to collect and process geospatial data to be used by driver assistive system, and the costs and time associated with collecting map data, and creating a map from that data. With cost data complete, counties can determine whether to acquire these systems.

Deployment of any system is driven by market demand and system cost. Initial deployment of the Intelligent Vehicle Lab Snowplow Driver Assistive System (DAS) was limited to a 45 mile section of Minnesota Trunk Highway 7 west of I-494 and east of Hutchinson MN. To better gage demand and functionality, St. Louis and Polk Counties in Minnesota operationally tested the system during the winter of 2003-2004; Polk County also tested during the winter of 2004-2005. Operational benefits were found to be drastically different in the two counties. Low visibility was not an issue with the St. Louis County snowplow routes, so the system offered few benefits. In contrast the topology of Polk county is flat, with almost no trees. High winds combined with few visual cues create significant low visibility conditions. Polk County was pleased with their original system, and obtained a second system and tested it operationally during the 2004-2005 winter. The experience of these two counties is documented in Volume One. A key component of the DAS is a high accuracy digital map. With the exception of the mapping process, the present cost of the DAS is well documented. This volume, Volume Two, describes a system designed to collect and process geospatial data to be used by driver assistive system, and the costs and time associated with collecting map data, and creating a map from that data. With cost data complete, counties can determine whether to acquire these systems.

Report #1 in Developing Intersection Decision Support Solutions. Minnesota's rural crash records were analyzed in order to develop a better understanding of crashes at rural intersections and their cause. The objective in studying the causes of crashes at rural intersections is to support development of technology based strategies to mitigate high crash rates. Since previous research found that 80% of intersection crashes at thru-STOP intersections may be related to selection of insufficient gaps, the development and validation of Intersection Decision Support (IDS) technology that assists in proper gap selection was identified as a primary goal. A database of over 3,700 intersections was examined. Using the critical crash rate as an indicator, 23 rural expressway intersections and 104 rural two-lane intersections were identified as unusually "dangerous" locations. Right angle crashes (which are most often related to gap selection) were observed to account for approximately 50% of all crashes at the "dangerous" intersections, up from 28% for all rural thru-STOP intersections. A specific intersection was identified, evaluated and then selected for testing IDS technologies that can track vehicles approaching on the major roadway, compute the gap and communicate the information to drivers stopped on the minor street waiting to enter the intersection. The data acquisition system to be installed will allow analysis of driver decision making behavior and study the effects of introducing an IDS technology under development at the University of Minnesota.

This project was divided into three phases. In phase 1 ten fatal run-off-road crashes were reconstructed from crash scene diagrams and investigation reports. We found evidence of excessive speed in five of these, and a failure to properly use seatbelts eight of the ten. For seven of these we found that barriers complying with Test Level 3 of NCHRP Report 350 would probably have stopped the crashing vehicle's encroachment. In phase 2 we developed a vehicle trajectory simulation model and used it reconstruct five fatal median-crossing crashes. We found clear evidence of excessive speed in one of these, and in three of the five the encroaching vehicle would probably have been restrained by Test Level 3-compliant barriers. In phase 3 five teams of traffic safety professionals reviewed accident reports from a sample of fatal rural crashes, with the aim of identifying possible causal factors and potential countermeasures. The most frequently identified causal factors were driver inexperience and failure to properly use restraints, while provision of rumble strips, improvements to roadsides or cross-slopes, and provision of guardrails or barriers were the most frequently-cited countermeasures.

This is Report #2 in the Series: Developing Intersection Decision Support Solutions. This project was a component of the Intersection Decision Support (IDS) effort conducted at the University of Minnesota. In this project, statistical modeling was applied to crash data from 198 two-way, stop-controlled, intersections on Minnesota rural expressways, in order to: (1) identify intersections that were plausible candidates for future IDS deployment; (2) develop a method for estimating the crash-reduction effect of IDS deployment; (3) develop a method for predicting the crash-reduction potential of IDS deployment, and (4) test the hypothesis that older drivers were over-represented in intersection crashes along US Trunk Highway 52. All these objectives were accomplished using hierarchical model structures similar to that employed in the Interactive Highway Safety Design Model. Five rural expressway intersections were identified as having crash frequencies that were atypically high, and this group included the intersection of US Trunk Highway 52 and Goodhue County highway 9, the site chosen for the prototype IDS deployment. It was then determined that a 3-year count of crashes after deployment would probably be sufficient to detect any crash reduction effect due to the IDS, although a reliable estimate of the magnitude of this effect would require a longer test period. Assuming that the effect of an IDS deployment would be to make the crash frequencies at treated intersections similar to that experienced by typical intersections, it was estimated that deployment of the IDS at the five high-crash intersections would, over a 15-year period, result in a reduction of about 308 crashes. Finally, using an induced-exposure approach, twelve intersections were identified as showing over-representation of older drivers, five of these being on US Trunk Highway 52.

Report #2 in the Series: Toward a Multi-State Consensus on Rural Intersection Decision Support. This project looked at various intersection data to find the best North Carolina intersection candidate for test deployment of Intersection Decision Support (IDS) technology, and found that US 74 and State Route 2210 is the best candidate.

Report #3 in the Series: Toward a Multi-State Consensus on Rural Intersection Decision Support. This project looked at various intersection data to find the best Michigan intersection candidate for test deployment of Intersection Decision Support (IDS) technology, and found that M-44 and Ramsdell Drive is the best candidate.

INV 805: This study evaluated the effectiveness of street lighting on isolated rural intersections in reducing nighttime crashes, using both a comparative analysis and a before-and-after study, and found that street lighting can reduce the number of crashes.

The Intersection Decision Support (IDS) research project is sponsored by a consortium of states (Minnesota, California, and Virginia) and the Federal Highway Administration (FHWA) whose objective is to improve intersection safety. The Minnesota team's focus is to develop a better understanding of the causes of crashes at rural unsignalized intersections and then develop a technology solution to address the cause(s). In the original study, a review of Minnesota's rural crash records and of past research identified poor driver gap selection as a major contributing cause of rural intersection crashes. Consequently, the design of the rural IDS technology has focused on enhancing the driver's ability to successfully negotiate rural intersections by communicating information about the available gaps in the traffic stream to the driver. In order to develop an IDS technology that has the potential to be nationally deployed, the regional differences at rural intersections must first be understood. Only then can a universal solution be designed and evaluated. To achieve this goal of national consensus and deployment, the University of Minnesota and the Minnesota Department of Transportation initiated a State Pooled Fund study, in which nine states are cooperating in intersection-crash research. This report documents the crash analysis phase of the pooled fund study for the State of Wisconsin.

This paper looks at alternatives for promoting and strengthening multimodal transportation in rural and small urban areas. It outlines 65 different innovative activities around the United States that have been undertaken to promote multimodalism in rural areas and smaller towns. These activities are grouped into six categories: improving transit options; accommodating alternative vehicles; supporting pedestrian and bicycle travel; multimodal land use planning; the use of financial incentives to promote multimodal land use development; and other alternatives that do not fit in these five categories. From this, six case studies have been developed. These case studies include retrofitting sidewalks in Olympia Washington: the network of interurban transit options in North Dakota; providing mileage reimbursement for seniors arranging their own rides in Mesa Arizona; the State of Oregon's "Main Street as a Highway" guidance for integrating highways into the fabric of smaller towns; the use to transportation impact fees to fund transportation infrastructure, including concurrency fees, development fees and special district fees; and a "Complete Streets" project in Clinton, Iowa.

The ALERT-2 system was redesigned to mitigate increased roll-throughs. With respect to technological advances, the ALERT-2 system improves many aspects of the basic technologies, providing higher system reliability, easier installation and maintainability, and better self-sustainability through redesign of the renewable energy application. To assess the driver behaviors at the test site, 13 months worth of video data and a survey of local residents were collected. This report describes the system development, implementation, and analysis of the video and survey data.

A number of studies have linked the benefits of roadway lighting to a reduction in crash rates at night for a variety of roadway types including rural intersections. Assessing the effectiveness of intersection lighting has primarily relied upon crash database modeling comparing lighted intersections to unlighted intersections. The current research effort gathered similar metrics for comparison but also measured the amount of lighting within isolated rural intersections. Sixty-three intersection locations were chosen for lighting measurement from six different counties within Minnesota. A vehicle mounted illuminance meter data collection system was used to collect data at each intersection. The data collection system utilized five separate illuminance meters and captured horizontal illuminance while driving through all 63 intersection locations. Following data collection, a series of negative binomial regression models were used to assess the horizontal lighting level in conjunction with the nighttime crash ratio, intersection configuration type, and proximity of an intersection to a curve in the roadway. The first model used data from the lighted an unlighted intersections. The results showed that across all intersections, an increase in the average horizontal illuminance (3.91 lux) by 1-lux (~0.09 fc) reduced nighttime crash rates by 9%. A second model used only lighted intersection data and showed an increase in 1-lux from average (6.41 lux) reduced crashes by 20%. A third and final model used unlighted intersections only. A 1-lux increase from average (0.20 lux) or increasing illuminance to lighted levels (as defined by the modeling), reduced nighttime crash ratios by 94%. Intersection configuration and proximity to curves also affected the nighttime crash ratios. The results of this effort are discussed in terms the impact of horizontal illuminance on crash rates. Additional items discussed include thresholds for minimum and maximum lighting levels and future research investigating and validating these efforts.

The Federal Highway Administration (FHWA) estimates that 58 percent of roadway fatalities are lane departures, while 40 percent of fatalities are single-vehicle run-off-road (SVROR) crashes. Addressing lane-departure crashes is therefore a priority for national, state, and local roadway agencies. Horizontal curves are of particular interest because they have been correlated with increased crash occurrence. This toolbox was developed to assist agencies address crashes at rural curves. The main objective of this toolbox is to summarize the effectiveness of various known curve countermeasures. While education, enforcement, and policy countermeasures should also be considered, they were not included given the toolbox focuses on roadway-based countermeasures. Furthermore, the toolbox is geared toward rural two-lane curves. The research team identified countermeasures based on their own research, through a survey of the literature, and through discussions with other professionals. Coverage of curve countermeasures in this toolbox is not necessarily comprehensive. For each countermeasure covered, this toolbox includes the following information: description, application, effectiveness, advantages, and disadvantages.

The effects of farm equipment on the structural behavior of flexible and rigid pavements were investigated in this study. The project quantified the difference in pavement behavior caused by heavy farm equipment as compared to a typical 5-axle, 80 kip semi-truck. This research was conducted on full scale pavement test sections designed and constructed at the Minnesota Road Research facility (MnROAD). The testing was conducted in the spring and fall seasons to capture responses when the pavement is at its weakest state and when agricultural vehicles operate at a higher frequency, respectively. The flexible pavement sections were heavily instrumented with strain gauges and earth pressure cells to measure essential pavement responses under heavy agricultural vehicles, whereas the rigid pavement sections were instrumented with strain gauges and linear variable differential transducers (LVDTs). The full scale testing data collected in this study were used to validate and calibrate analytical models used to predict relative damage to pavements. The developed procedure uses various inputs (including axle weight, tire footprint, pavement structure, material characteristics, and climatic information) to determine the critical pavement responses (strains and deflections). An analysis was performed to determine the damage caused by various types of vehicles to the roadway when there is a need to move large amounts agricultural product.

Appropriate deceleration on approaches to roundabouts is primarily accomplished through the use of applicable geometric design principles; however; traffic control devices (specifically signing and markings on the approach) also serve a vital role in communicating to the approaching driver what speed profile should be anticipated. This report provides a resource for engineers to identify and select appropriate speed-reduction treatments for high-speed approaches to roundabouts. The research examines best practices and research literature on speed-reduction techniques for high-speed approaches for all intersection types; as well as treatments for work zones and horizontal curves. Based on the findings from these efforts; the report summarizes a selection of treatments including traditional signs with and without beacons; pavement markings; illumination; speed-activated signs; and transition zones. Information on the effectiveness of these treatments; as well as potential costs of installation and maintenance; is provided for the practitioner to determine which treatment(s) best suit the site under consideration. Guidance is also provided for the methodology of conducting a speed study to determine the speed characteristics of a site; as well as links to resources for additional information. The project identifies a number of research needs specific to particular treatments as well as the general need for field research of the recommended countermeasures specifically on approaches to high-speed rural roundabouts.

The Minnesota Department of Transportation (MnDOT) is investing significant resources in intersection collision warning systems (ICWS) based on early indications of effectiveness. However; the effectiveness is not well documented; and negative changes in driver behavior at treatment intersections may affect drivers overall; resulting in a spillover effect. Moreover; the effectiveness of ICWS may decrease if drivers do not perceive a change in the dynamic messages. Therefore; the objectives of this research were to (1) evaluate driver behavior at mainline and stop-controlled approaches for intersections with and without ICWS and (2) assess the traffic volume range and limits where the system is nearly continuously activated and is likely to lose its effectiveness. Video data were collected at five treatment and corresponding control intersections; and various metrics were used to compare changes in driver behavior. In general; no negative behaviors were noted for either treatment or control intersections.

At almost 80 million people, the Millennial generation will have a growing impact on many aspects of society, including transportation needs. Research (conducted largely in urban areas) suggests that this generation has different lifestyle trends than previous generations, which has created a need to re-evaluate transportation policy and planning. The objective of this project is to understand whether Millennials in small urban and rural communities have the same mobility mindset as those in large cities. Data was collected from survey respondents living in both urban and rural areas from multiple generations in Minnesota, Montana, Washington and Wisconsin. The results indicate that there were clear differences between urban and rural Millennials with respect to educational attainment, student loans, income, use of technology and their expectation for moving. These differences imply that alternative options for transportation may not be as viable in rural areas as compared with urban areas. However, the fact that rural Millennial survey respondents reported households with zero vehicles across all area types and that rural Generation X survey respondents had a higher percentage reporting that they preferred a bicycle to travel to school than their urban counterparts suggests that there are opportunities to provide alternatives that people will make use of in rural environments. Furthermore, with a higher number of households in rural areas reporting an annual income of less than $20,000, which likely limits their transportation options, there is clearly a need to consider how to allow these households to access healthcare, education and employment.