Browsing by Author "Davis, Brian"

Now showing 1 - 16 of 16
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    Aggregating VMT within Predefined Geographic Zones by Cellular Assignment: A Non-GPS-Based Approach to Mileage- Based Road Use Charging
    (Intelligent Transportation Systems Institute, Center for Transportation Studies, University of Minnesota, 2012-08) Davis, Brian; Donath, Max
    Currently, most of the costs associated with operating and maintaining the roadway infrastructure are paid for by revenue collected from the motor fuel use tax. As fuel efficiency and the use of alternative fuel vehicles increases, alternatives to this funding method must be considered. One such alternative is to assess mileage based user fees (MBUF) based on the vehicle miles traveled (VMT) aggregated within the predetermined geographic areas, or travel zones, in which the VMT is generated. Most of the systems capable of this use Global Positioning Systems (GPS). However, GPS has issues with public perception, commonly associated with unwanted monitoring or tracking and is thus considered an invasion of privacy. The method proposed here utilizes cellular assignment, which is capable of determining a vehicle’s current travel zone, but is incapable of determining a vehicle’s precise location, thus better preserving user privacy. This is accomplished with a k-nearest neighbors (KNN) machine learning algorithm focused on the boundary of such travel zones. The work described here focuses on the design and evaluation of algorithms and methods that when combined, would enable such a system. The primary experiment performed evaluates the accuracy of the algorithm at sample boundaries in and around the commercial business district of Minneapolis, Minnesota. The results show that with the training data available, the algorithm can correctly detect when a vehicle crosses a boundary to within ±2 city blocks, or roughly ±200 meters, and is thus capable of assigning the VMT to the appropriate zone. The findings imply that a cellular-based VMT system may successfully aggregate VMT by predetermined geographic travel zones without infringing on the drivers’ privacy.
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    Deploy and Test a Smartphone-Based Accessible Traffic Information System for the Visually Impaired
    (Minnesota Department of Transportation, 2020-10) Liao, Chen-Fu; Davis, Brian
    An increasing number of Accessible Pedestrian Signals (APS) have been installed at new or upgraded intersections to assist people with vision impairment to navigate streets. For un-signalized intersections and intersections without APS, people with vision impairment have to rely on their own orientation and mobility skills to gather necessary information to navigate to their destinations. Previously, a smartphone-based accessible pedestrian system was developed to support wayfinding and navigation for people with vision impairment at both signalized and un-signalized intersections. A digital map was also created to support the wayfinding app. This system allows a visually impaired pedestrian to receive signal timing and intersection geometry information from a smartphone app for wayfinding assistance. A beacon using Bluetooth Low Energy (BLE) technology helps to identify a pedestrian's location when he or she travels in a GPS-unfriendly environment. A network of Bluetooth beacons ensures that correct traffic information is provided to the visually impaired at the right location. This project leverages the previous work by installing the system at a number of intersections in downtown Stillwater, Minnesota, where MnDOT operates the signalized intersections. In this study, researchers interface with the traffic controllers to broadcast traffic signal phasing and timing (SPaT) information through a secured and private wireless network for visually impaired users. The aim is to test the smartphone-based accessible system and evaluate the effectiveness and usefulness of the system in supporting wayfinding and navigation while the visually impaired travel through signalized and un-signalized intersections.
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    Deployment of a Snowplow Driver-Assist System
    (Minnesota Department of Transportation, 2023-06) Davis, Brian; Schwieters, Katelyn; Morris, Nichole L.; Donath, Max
    Snowplow operators are often tasked with clearing snow from roadways under challenging conditions. One such situation is low visibility due to falling or blowing snow that makes it difficult to navigate, stay centered in the lane, and identify upcoming hazards. To support snowplow operators working in these conditions, University of Minnesota researchers developed a snowplow driver-assist system that provides the operator with visual and auditory information that is suitable for low-visibility situations. A lane-guidance system uses high-accuracy Global Navigation Satellite System (GNSS) and maps of the roadway to provide information to drivers about their lateral positions. A forward-obstacle-detection system uses forward-facing radar to detect potential hazards in the roadway. The design of the system, and in particular its interface, is guided by extensive user testing to ensure the system is easy to understand, easy to use, and well liked among its users. The system was deployed in two phases over the 2020-2021 and 2021-2022 winter seasons. In total, nine systems were deployed on snowplows across Minnesota, four in the first winter season and an additional five in the second. Participating truck stations represented all eight MnDOT districts as well as Dakota County. Over the course of the deployment, additional user feedback was collected to identify system strengths and areas for improvement. The system was found to be a cost-effective addition to snowplows that increase driver safety, reduce plow downtime, and increase driver efficacy for plowing operations, thus providing support to operators working in demanding, low-visibility conditions.
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    Development of a Mobile App for Reporting Work Zone Intrusions
    (Minnesota Department of Transportation, 2024-01) Davis, Brian; Morris, Nichole L.; Craig, Curtis; Schumacher, John; Khoday, Annaika
    Work zone intrusions represent a significant safety risk to workers. To help better understand these situations, the Minnesota Department of Transportation partnered with the University of Minnesota to create a method to document intrusion events. This information provides a deeper understanding of the circumstances under which these events occur and enables data-driven decision making when considering ways to reduce or mitigate work zone intrusions. This work focuses on the development of a mobile smartphone app that allows workers to report intrusions from the field immediately after they occur, allowing for timely and accurate intrusion reporting. The work zone intrusion mobile app is developed using an iterative, user-centered design process that solicits feedback from work zone personnel, supervisors, and work zone safety stakeholders at every step in the process. The app uploads completed report data to the existing eSAFE system, allowing for a single repository of collected intrusion report data. To support deployment of the system, training workshops and supporting training and communications materials are created for distribution among users. Throughout the development and deployment of the app, user feedback shows that the app is easy to use and well liked.
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    Development of a Sensor Platform for Roadway Mapping: Part A - Road Centerline and Asset Management
    (Center for Transportation Studies, University of Minnesota, 2014-06) Davis, Brian; Donath, Max
    Collecting information about the roadway infrastructure is a task that DOTs at all governmental levels need to accomplish. One way to increase the operational efficiency of these efforts is to use a relatively inexpensive mobile data collection platform that acquires information that is general enough to serve multiple purposes. The design and evaluation of one such platform that costs roughly $40,000 is described. It primarily consists of a differential GPS receiver providing vehicle location, and a LIDAR scanner that generates geometric profiles of the area between the vehicle and just beyond the road’s edge. The vehicle collects data along the road by driving it in both directions. The system post-processes the data to automate feature extraction. For roads with simple geometry such as two-lane, undivided highways, the road’s centerline can be calculated by finding the midline between the vehicle’s paths from each direction of travel. Algorithms process the LIDAR scans to automatically detect the presence of curbs and guardrails, which is then combined with location information to yield the position of these features in world coordinates. The centerline calculation was determined to be accurate to within 6 cm in areas where its use was applicable. Curbs and guardrails were generally detected with an accuracy of better than 10 cm. The results demonstrate that it is feasible to use a relatively inexpensive mobile data collection system to acquire road centerline and roadside features such as curbs and guardrails.
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    Development of a Sensor Platform for Roadway Mapping: Part B – Mapping the Road Fog Lines
    (Minnesota Department of Transportation, 2015-04) Davis, Brian; Donath, Max
    Our objective is the development and evaluation of a low-cost, vehicle-mounted sensor suite capable of generating map data with lane and road boundary information accurate to the 10 cm (4 in) level. Such a map could be used for a number of different applications including GNSS/GPS based lane departure avoidance systems, smart phone based dynamic curve speed warning systems, basemap improvements, among others. The sensor suite used consists of a high accuracy GNSS receiver, a side-facing video camera, and a computer. Including cabling and mounting hardware, the equipment costs were roughly $30,000. Here, the side-facing camera is used to record video of the ground adjacent to the passenger side of the vehicle. The video is processed using a computer vision algorithm that locates the fog line within the video frame. Using vehicle position data (provided by GNSS) and previously collected video calibration data, the fog line is located in real-world coordinates. The system was tested on two roads (primarily two-lane, undivided highway) for which high accuracy (<10 cm) maps were available. This offset between the reference data and the computed fog line position was generally better than 7.5 cm (3 in). The results of this work demonstrate that it is feasible to use a camera to detect the position of a road’s fog lines, or more broadly any other lane markings, which when integrated into a larger mobile data collection system, can provide accurate lane and road boundary information about road geometry.
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    Development of a Workshop on Automated Vehicle Technologies
    (Center for Transportation Studies, University of Minnesota, 2019-07) Davis, Brian; Johnson, Reed
    Connectivity and automation in vehicles have the potential to change nearly every aspect of our transportation system. Vehicles with these capabilities are already being tested on public roads and are beginning to enter the national fleet. These vehicles have the potential to bring numerous benefits to the public, but these benefits come with tradeoffs that must be carefully considered by transportation professionals.This project focuses on the development and delivery of a two-day workshop on connected and automated vehicles (CAVs) for an audience of public transportation professionals. This workshop was designed to not only provide an overview of CAV technologies but to also to take an in-depth look at Global Navigation Satellite Systems, LIDAR, and the software and algorithms that use these sensors for localization and navigation. The goal of the workshop was to help develop technical literacy about these technologies among workshop participants to provide context when encountering CAV technologies. A workshop was developed that incorporates classroom lectures and demonstrations using a robotic unmanned ground vehicle. A pilot offering of the workshop was delivered in May 2019, which was attended by eight public transportation professionals representing different agencies at different levels of government. Participant feedback was collected to evaluate the efficacy of the workshop. Responses were almost exclusively positive, highlighting participants’ interest in both classroom sessions and demonstrations. Using constructive feedback, improvements have been identified for future offerings. Workshop participants found the workshop to be interesting and reported learning about the topics covered, motivating future offerings.
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    Development of a Workshop on Automated Vehicle Technologies
    (Center for Transportation Studies, University of Minnesota, 2019-07) Davis, Brian; Johnson, Reed
    Connectivity and automation in vehicles have the potential to change nearly every aspect of our transportation system. Vehicles with these capabilities are already being tested on public roads and are beginning to enter the national fleet. These vehicles have the potential to bring numerous benefits to the public, but these benefits come with tradeoffs that must be carefully considered by transportation professionals. This project focuses on the development and delivery of a two-day workshop on connected and automated vehicles (CAVs) for an audience of public transportation professionals. This workshop was designed to not only provide an overview of CAV technologies but to also to take an in-depth look at Global Navigation Satellite Systems, LIDAR, and the software and algorithms that use these sensors for localization and navigation. The goal of the workshop was to help develop technical literacy about these technologies among workshop participants to provide context when encountering CAV technologies. A workshop was developed that incorporates classroom lectures and demonstrations using a robotic unmanned ground vehicle. A pilot offering of the workshop was delivered in May 2019, which was attended by eight public transportation professionals representing different agencies at different levels of government. Participant feedback was collected to evaluate the efficacy of the workshop. Responses were almost exclusively positive, highlighting participants' interest in both classroom sessions and demonstrations. Using constructive feedback, improvements have been identified for future offerings. Workshop participants found the workshop to be interesting and reported learning about the topics covered, motivating future offerings.
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    Development of Driver Assistance Systems to Support Snowplow Operations
    (Center for Transportation Studies, University of Minnesota, 2018-08) Liao, Chen-Fu; Morris, Nichole L.; Achtemeier, Jacob; Alexander, Lee; Davis, Brian; Donath, Max; Parikh, Gordon
    Snowplow operators are often tasked with numerous monitoring and operational activities that they need to do simultaneously while removing snow and spreading deicing agents on the road. Driver assist systems were considered for 3 applications: gang plowing, backup assist, and lane boundary guidance. We evaluated the system performance and position accuracy of commercially available Dedicated Short Range Communication (DSRC) Onboard Units (OBU) for gang plowing. Our results indicated that the positioning accuracy of the OBUs was inadequate for providing the plow operator with sufficient information to maintain spacing between two vehicles. The backup assist system and lane boundary guidance system were developed and successfully deployed to support snowplow operations. Human factors studies were also conducted using a driving simulator to better understand the needs prior to designing an appropriate Human Machine Interface (HMI) for these plow operations. The radar-based backup assist system was installed on a snowplow that operates on Highway 169. The backup assist system provides an audio warning to the operator to look at the display from a rear-view camera when an object is detected. The Global Navigation Satellite System (GNSS)-based lane boundary guidance system was developed to assist plow operations when visibility is poor and lane boundary cues are limited. The lane boundary guidance system was installed on a second snowplow operating on MN-25 running between Belle Plaine and Green Isle. The lane boundary guidance received the most positive feedback from operators and is recommended for further development.
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    Environmental Impacts of Smart Irrigation and Mowing Height in Kentucky Bluegrass Lawns
    (2019-11) Sandor, Dan; Horgan, Brian; Davis, Brian
    Kentucky bluegrass (Poa pratensis L.; KBG) is the most widely used turfgrass species in Minnesota lawns, requiring routine cultural management inputs such as mowing and irrigation to maintain acceptable turfgrass quality. Previous research has suggested raising mowing heights and using improved irrigation technology to reduce inputs without sacrificing lawn quality. Limited information exists regarding the combined aesthetic impacts of mowing height + smart irrigation on lawn mowing requirements and their affects also their potential combined environmental impacts using improved irrigation and mowing practices.
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    Evaluation of Low-Cost, Centimeter-Level Accuracy OEM GNSS Receivers
    (Minnesota Department of Transportation, 2018-02) Jackson, John; Saborio, Ricardo; Ghazanfar, Syed Anas; Gebre-Egziabher, Demoz; Davis, Brian
    This report discusses the results of a study to quantify the performance of low-cost, centimeter-level accurate Global Navigation Satellite Systems (GNSS) receivers that have appeared on the market in the last few years. Centimeter-level accuracy is achieved using a complex algorithm known as real-time kinematic (RTK) processing. It involves processing correction data from a ground network of GNSS receivers in addition to the signals transmitted by the GNSS satellites. This makes RTK-capable receivers costly (in excess of $10,000) and bulky, making them unsuitable for cost- and size-sensitive transportation applications (e.g., driver assist systems in vehicles). If inexpensive GNSS receivers capable of generating a position solution with centimeter accuracy were widely available, they would push the GNSS revolution in ground transportation even further as an enabler of safety enhancements such as ubiquitous lane-departure warning systems and enhanced stability-control systems. Recently manufacturers have been advertising the availability of low-cost (< $1,000) RTK-capable receivers. The work described in this report provides an independent performance assessment of these receivers relative to high-end (and costly) receivers in realistic settings encountered in transportation applications.
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    Improvement of Driving Simulator Eye Tracking Software
    (Center for Transportation Studies, University of Minnesota, 2019-06) Davis, Brian; Morris, Nichole L.; Achtemeier, Jacob D.; Easterlund, Peter
    This work focuses on improving the eye tracking analysis tools used with the HumanFIRST driving simulator. Eye tracking is an important tool for simulation-based studies. It allows researchers to understand where participants are focusing their visual attention while driving. The eye tracking system provides a nearly continuous record of the direction in which the driver is looking with respect to real-world coordinates. However, this by itself does not give any information about the objects at which the driver is looking. To determine when a driver is fixated on a given element in the simulated world (e.g., a vehicle or sign), additional processing is necessary. Current methods to process this data are time and resource intensive, requiring a researcher to manually review the eye tracking data. This motivates an automated solution that can automatically and programmatically combine eye tracking and simulator data to determine at which object(s) (either in the real world or the simulated world) the driver is looking. This was accomplished by developing and implementing software capable of providing useful eye tracking data to researchers without requiring time and resource intensive human intervention and hand coding of data. The data generated by the analysis software was designed to provide a set of summary statistics and metrics that will be useful across different simulation studies. Additionally, visualization software was created to allow researchers to view key simulator and eye tracking data for context or insight or to identify and characterize anomalies in the analysis software. Overall, the software implemented will increase the efficiency with which eye tracking data can be used alongside simulator data.
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    In-Vehicle Dynamic Curve-Speed Warnings at High-Risk Rural Curves
    (Minnesota Department of Transportation, 2018-03) Davis, Brian; Morris, Nichole L.; Achtemeier, Jacob D.; Patzer, Brady
    Lane-departure crashes at horizontal curves represent a significant portion of fatal crashes on rural Minnesota roads. Because of this, solutions are needed to aid drivers in identifying upcoming curves and inform them of a safe speed at which they should navigate the curve. One method for achieving this that avoids costly infrastructure-based methods is to use in-vehicle technology to display dynamic curve-speed warnings to the driver. Such a system would consist of a device located in the vehicle capable of providing a visual and auditory warning to the driver when approaching a potentially hazardous curve at an unsafe speed. This project seeks to determine the feasibility of in-vehicle dynamic curve-speed warnings as deployed on a smartphone app. The system was designed to maximize safety and efficacy to ensure that system warnings are appropriate, timely, and non-distracting to the driver. The developed system was designed and implemented based on the results of a literature survey and a usability study. The developed system was evaluated by 24 Minnesota drivers in a controlled pilot study at the Minnesota Highway Safety and Research Center in St. Cloud, Minnesota. The results of the pilot study showed that, overall, the pilot study participants liked the system and found it useful. Analysis of quantitative driver behavior metrics showed that when receiving appropriately placed warnings, drivers navigated horizontal curves 8-10% slower than when not using the system. These findings show that such a curve-speed warning system would be useful, effective, and safe for Minnesota drivers.
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    Innovative Technology Workshop on 3D LIDAR
    (Center for Transportation Studies, University of Minnesota, 2016-06) Davis, Brian
    The use of LIDAR is becoming more common among state, county, and local agencies. It presents a means for collecting a great deal of information about the geometry of a road, its surrounding area, and depending on the sensors used, real-time 3D information about vehicle, cyclist, and pedestrian movements. The main focus of this project was to develop and conduct two workshops in Minnesota for public DOT and GIS professionals to provide information on the state of the art in mobile LIDAR scanning. Topics included the basics of LIDAR operation, an overview of currently available hardware, as well as current and future applications of the technology. Additionally, the workshops featured a live demonstration of a Velodyne HDL-64E 3D LIDAR scanner. A sample application was developed to both demonstrate and better understand the capabilities of a real-time 3D LIDAR scanner. This work focused on developing a system capable of automatically collecting vehicle trajectories through intersections using 3D LIDAR data. This application showed that LIDAR might be a suitable tool for collecting traffic data and provided valuable information about the strengths and limitations of such a system. This project was designed to provide transportation and GIS professionals with accurate, current, and applicable information about LIDAR systems. To accomplish this, existing LIDAR knowledge was combined with market survey research as well as with new information gathered through the process of creating a sample application. This knowledge was aggregated and used to create a workshop that was informative and well received by participants.
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    Teen Driver Support System Technology Transfer
    (Center for Transportation Studies, University of Minnesota, 2019-07) Davis, Brian
    The Teen Driver Support System (TDSS) is a smartphone application designed to provide real-time, in-vehicle feedback to novice drivers about their driving behavior to help them make safer driving decisions. The app provides warnings to the driver using in-phone sensors and maps to determine when the driver engages in in risky behavior. TDSS was evaluated in a field operational test that showed the system successfully helps reduce certain risky behaviors among teens using the system. The project documented in this report seeks to extend prior work on the system to make it suitable for future applications. This work included adding features, fixing bugs, and rebranding the system as Road Coach. It also included identifying and pursuing possible future applications of the technology. These efforts enabled the app’s use in a new application focused on providing in-vehicle feedback to older drivers. This application was evaluated as part of two separate projects. These usability and field operational test projects had positive results, notably high user acceptance and system efficacy in reducing certain risky driving behaviors. Future work in this area will continue to pursue this application of the technology as well as others.
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    Work Zone Intrusion Report Interface Design
    (Minnesota Department of Transportation, 2018-02) Craig, Curtis M.; Morris, Nichole L.; Libby, David A.; Davis, Brian
    While necessary for roadways, work zones present a safety risk to crew. Half of road workers deaths between 2005 and 2010 were due to collisions with motorists intruding on the work zone. Therefore, addressing intrusions is an important step for ensuring a safe work environment for crewmembers. However, a recent research synthesis at the Minnesota Department of Transportation found that few states had an explicit method for systematically collecting work zone intrusion data. The purpose of this work zone intrusion interface design project was to design an efficient, comprehensive, and user-friendly reporting system for intrusions in work zones. A user-centric, iterative design process was employed to design an adaptable web-based and paper report to account for simple documentation of intrusions not deemed a threat to worker safety and a detailed report for more thorough documentation of serious intrusion events. Final recommendations include organizational changes and support to encourage workers to complete the form and provide valuable data to the state.