Browsing by Subject "Work zones"

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Development and Field Demonstration of DSRC Based V2V-Assisted V2I Traffic Information System for the Work Zone
(Intelligent Transportation Systems Institute, Center for Transportation Studies, University of Minnesota, 2012-06) Maitipe, Buddhika; Ibrahim, Umair; Hayee, M. Imran
This report describes the architecture, functionality and the field demonstration results of a newly developed DSRC based V2I work zone traffic information system with V2V assistance. The developed system can automatically acquire important work zone travel information, e.g., the travel time (TT) and the starting location of congestion (SLoC), and relay them back to the drivers approaching the congestion site. Such information can help drivers in making informed decisions on route choice and/or preparing for upcoming congestion. Previously, we designed such a system using DSRC based V2I-only communication, which could not handle longer congestion lengths and the message broadcast range was also very limited. Our current system, on the other hand, can achieve much longer broadcast range (up to a few tens of kms), and can handle much longer congestion coverage length (up to a few kms) by incorporating DSRC based V2I communication with V2V assistance. The new system is also portable and uses only one RSU, which can acquire traffic data by engaging the vehicles traveling on the roadside whether within or outside of its direct wireless access range. From the traffic data, it estimates important traffic parameters, i.e., TT and SLoC, and periodically broadcasts them back to the vehicles approaching the congestion well before they enter the congested area. The results from the field demonstration have indicated that new system can adapt to dynamically changing work zone traffic environments and can handle much longer congestion lengths as compared to the previous system using V2I-only communication without V2V assistance.
Development and Field Demonstration of DSRC-Based V2I Traffic Information System for the Work Zone
(2010-12) Maitipe, Buddhika; Hayee, M. Imran
This report describes the architecture, functionality and the field demonstration of a newly developed dedicated short-range communication (DSRC)-based Vehicle to Infrastructure (V2I) communication system for improving traffic efficiency and safety in the work-zone related congestion buildup on US roadways. The goal was to develop a portable system that can be easily deployed at a work zone site to acquire and communicate important travel information, e.g., travel time (TT) and start of congestion (SoC) location to the driver. By providing this information, i.e., SoC location and TT, drivers can make informed decisions on route choice and be prepared for upcoming congestion. The system is composed of a portable road-side unit (RSU) that can engage the on board units (OBUs) of the traveling vehicles using DSRC technology to acquire necessary traffic data (speed, time, and location). From the acquired data, the RSU periodically estimates the SoC location and TT that are broadcast to all vehicles in its coverage range. An OBU receiving the broadcast message calculates the distance to the SoC location. The distance to the SoC location and TT are then relayed to the driver, who can make smart decisions regarding whether to seek an alternate route and when to expect a sudden speed reduction. Results from the field demonstration have shown that the developed system can adapt to changing work-zone environments smoothly under various congestion patterns on the road.
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.
Development of a Navigation System Using Smartphone and Bluetooth Technologies to Help the Visually Impaired Navigate Work Zones Safely
(Minnesota Department of Transportation, 2014-02) Liao, Chen-Fu
According to statistics from the Federal Highway Administration (FHWA), each year approximately 17% of all work zone fatalities are pedestrians. People who are visually impaired often encounter physical and information barriers that limit their accessibility and mobility. A survey was conducted among 10 visually impaired participants as a starting point to understand their challenges and what types of information are helpful in providing bypass or routing instructions to them around work zones. The survey results were incorporated into development of guiding documents in determining information elements that are essential and useful for providing routing instructions to the visually impaired around work zones. Building on our previous efforts to provide geometry and signal timing to the visually impaired at signalized intersections, a smartphone-based navigation system was developed and integrated with navigational audible information to alert pedestrians at decision points prior to their arrival at a work zone. The recommended message elements from survey results were implemented in a smartphone app that uses GPS and Bluetooth technologies to determine a user’s location. When a work zone is detected, the smartphone will vibrate to alert users and the app will then announce a corresponding audible message to users. The visually impaired users can perform a single tap on the smartphone to repeat the messages, if needed. Functionality testing and system validation of the smartphone app were performed by attaching four Bluetooth beacons to light posts near a construction site in St. Paul, MN. Additional research is needed to conduct experiments with visually impaired users and evaluate system reliability and usefulness.
Development of Hybrid DSRC-PCMS Information Systems for Snowplow Operations and Work Zones
(Intelligent Transportation Systems Institute, Center for Transportation Studies, University of Minnesota, 2013-02) Ibrahim, Umair; Hayee, M. Imran
The future deployment of dedicated short range communication (DSRC) technology requires that DSRC-based applications are integrated with existing traffic management techniques so that non-DSRC-equipped vehicles at the early stage of DSRC deployment can also reap the potential benefits of DSRC technology. We have successfully developed and field demonstrated a hybrid traffic-information system combining DSRC technology and portable changeable message signs (PCMS) for work zone environment to improve traffic mobility, and thereby, driver safety. The developed system uses DSRC-based V2I and V2V communication to acquire travel safety parameters such as travel time (TT) and starting location of congestion (SLoC), and disseminate these parameters to both DSRC-equipped vehicles and DSRC-equipped PCMSs, which are strategically placed alongside the road. Using the DSRC-PCMS interface designed for this purpose, PCMSs can receive these travel safety parameters from nearby DSRC-equipped vehicles on the road via DSRC-based V2V communication, and display them for the drivers of the vehicles lacking DSRC capability. Such a system can be useful for an early stage of DSRC deployment when the DSRC market penetration is low. Additionally, a rigorous analysis has been conducted to investigate the minimum DSRC market penetration rate needed for successful functionality of the developed system with respect to both acquisition and dissemination of TT and SLoC. Using realistic traffic flow model, guidelines are developed to estimate a minimum DSRC penetration rate needed to deploy the developed system for a variety of traffic scenarios on a given work zone road.
Evaluation of the Smart Work Zone Speed Notification System
(Minnesota Department of Transportation., 2019-06) Hourdos, John; Parikh, Gordon; Dirks, Peter; Lehrke, Derek; Lukashin, Pavel
The Smart Work Zone Speed Notification (SWZSN) system aims to alleviate congestion, queuing, and rear end crashes in work zones by informing drivers of the speed of the downstream segment using a type of portable Intelligent Lane Control System (ILCS), Portable Changeable Message Signs (PCMS). The hypothesis was that drivers, knowing the speed up to 1 mile downstream, will slow down early or at least be alert and perform smoother decelerations. Video of the SWZSN was analyzed over two years of operation by the Minnesota Traffic Observatory. Overall, the system resulted in beneficial reductions of selected decelerations by the drivers. In situations where the messages communicated to the drivers were consistent and accurate, reductions of more than 30% in the selected deceleration rates were observed. Unfortunately, there were several cases where counterproductive or misleading messages were communicated to the drivers, prompting relative increases to the selected deceleration rates. The most important observation, stemming from both positive and negative influences, was that the speed notification system was noticed by drivers and resulted in a statistically significant influence on driving behavior, unlike other driver alert systems.
Examining the Impact of ASE (Automated Speed Enforcement) in Work Zones on Driver Attention
(Minnesota Department of Transportation, 2016-01) Morris, Nichole L.; Cooper, Jennifer L.; Ton, Alice; Plummer, John Paul; Easterlund, Peter
Each year, there are over 500 fatal crashes in work zones in the U.S., with over 100 road construction workers killed on work sites (NSC, 2011; FARS, 2011). Speed and distraction are among the top contributing factors to work zone crashes (Garber & Zhao, 2002; Mountain, Hirst, & Maher, 2005; Wilson, Willis, Hendrikz, Le Brocque, & Bellamy, 2006). The purpose of this study was to investigate the impact of different types of speed enforcement methods on driver attention in work zones. The investigation not only examined enforcement methods currently used in Minnesota, but also examined how implementing automated speed enforcement (ASE), which is not currently used in Minnesota, may influence driver attention and behavior in simulated work zones. Overall, the results do not appear to support the hypothesis that ASE without dynamic speed display sign (DSDS) improves driver attention in work zones. There is some evidence, however, that drivers did heighten their visual attention in work zones with ASE+DSDS enforcement. Drivers fixated on the secondary task display less frequently in the ASE+DSDS condition compared to other enforcement types while they traveled in the downstream portion of the work zone. The largest effects of the study were found among the age groups, with younger and older drivers exceeding the speed limit most often and varying their speed slightly depending on the type of enforcement present. Middle-aged drivers exhibited the greatest speed control and tended to abide by the speed limit to the same extent regardless of the type of enforcement present.
Influence of Autonomous and Partially Autonomous Vehicles on Minnesota Roads
(Minnesota Department of Transportation, 2023-05) Espindola, Andre; Alexander, Lee; Rajamani, Rajesh
This project focuses on experimental tests of the performance characteristics of autonomous vehicles (AVs) on highways and local roads in Minnesota. The project provides detailed data characterizing AV performance, which in turn can be used to inform the transportation community on implications for infrastructure maintenance, winter road maintenance, work zone guidelines, safety, and traffic capacity. The experimental work presented here makes use of a new autonomous vehicle purchased by the Center for Transportation Studies at the University of Minnesota. The key aspects of the autonomous functions of the vehicle studied in this project include winter performance and implications for road maintenance, characterization of the driving performance of the AV and its likely influence on safety, traffic flow and fuel economy, and the ability of the AV to handle work zones and the implications on changes needed to the guidelines for work zones. The project documents the major challenges and obstacles ahead in the way of true autonomy on Minnesota roads, but also outlines further areas for research with which it will be possible to facilitate the improvement of the capabilities of autonomous vehicles in Minnesota in the future.
Investigating the Effectiveness of Using Bluetooth Low-Energy Technology to Trigger In-Vehicle Messages in Work Zones
(Minnesota Department of Transportation, 2016-12) Liao, Chen-Fu; Donath, Max
In order to reduce risky behavior around workzones, this project examines the effectiveness of using invehicle messages to heighten drivers’ awareness of safety-critical and pertinent workzone information. This investigation centers around an inexpensive technology based on Bluetooth low-energy (BLE) tags that can be deployed in or ahead of the workzone. A smartphone app was developed to trigger nondistracting, auditory-visual messages in a smartphone mounted in a vehicle within range of the BLE workzone tags. Messages associated with BLE tags around the workzone can be updated remotely in real time and as such may provide significantly improved situational awareness about dynamic conditions at workzones such as: awareness of workers on site, changing traffic conditions, or hazards in the environment. Experiment results indicate that while travelling at 70 mph (113 km/h), the smartphone app is able to successfully detect a long-range BLE tag placed over 410 feet (125 meters) away on a traffic barrel on a roadway shoulder. Additional experiments are being conducted to validate the system performance under different roadway geometry, traffic, and weather conditions.
Lighted Guidance Devices: Intelligent Work Zone Traffic Control
(Minnesota Department of Transportation, 1995-06) Vercruyssen, Max; Williams, Gayna; Wade, Michael G.
Annually, thousands of highway workers risk serious injury and death from drivers who enter work zones too fast or accelerate after entering the zone and then, because of their excess speed relative to the environmental limitations, have insufficient time to avoid accidents in the zone. Slow-moving vehicles are a problem in reducing traffic flow. This research investigated the effectiveness of a system of pulsing lights, that gave the illusion of movement (Phi phenomenon), in causing drivers to unknowingly synchronize their vehicle speed with the light pulses. Forty drivers participated: 20 young (10 female, 10 male; 21-42 years) and 20 older adults (10 female, 10 male; 55-87 years). Each participant made 15 passes through the work zone: a control pass with stationary white lights, two control passes with no lights, and 12 passes of test conditions -- 2 colors (red & green) x 3 apparent pulse speeds (-80, 0, & +80 mph) x 2 zone entry speeds (40 & 70 mph). Age, sex, and zone entry speed differences were found, but overall, (1) backward moving lights (-80 mph) caused drivers to reduce their vehicle speed, (2) forward moving lights (+80 mph) caused drivers to increase their vehicle speed, (3) stationary light and control lights had little or no effect, and (4) green produced stronger effects than red. Backward moving lights caused the greatest slowing in the young while forward moving lights caused the greatest acceleration in the old males and young females.
Low-Cost Portable Video-Based Queue Detection for Work- Zone Safety
(2011-01) Morris, Ted; Schwach, Jory A.; Michalopoulos, Panos G.
Highway work-zone safety is a major concern for government agencies, the legislature, and the traveling public. Several work zone intelligent transportation systems (WZITS) have been developed as a safety countermeasure to warn drivers of dangerous traffic conditions. Unfortunately, the effectiveness of a WZTIS is diminished if the actual traffic flow conditions do not correspond with the sensor information leading to false warnings; these confuse drivers and reduce the credibility of the system, which is often ignored. This can lead to situations where drivers crash into work-zone areas because they are unprepared to stop. The national cost of crashes due to this was estimated to be nearly $2.5 billion. Such “dangerous” traffic conditions are typically characterized by unpredictable queue formations that propagate rapidly into higher speed traffic immediately upstream from the active work zone. False positives or missed warnings could be reduced if the location of queue tails in addition to vehicle speeds in proximity to the active work zone can be accurately detected. In this study, a low-cost rapidly deployable and portable queue detection WZITS warning system is proposed. To demonstrate WZITS feasibility, a queue detection algorithm was designed and tested using widely available, field proven, machine vision hardware that can be integrated into the current portable system prototype, using video data collected in the field from the portable device. The warning trigger generated by the algorithm can then be transmitted to a remote upstream location for triggering roadside emergency warning devices (such as VMS, flashers, etc.).
Options for Automated Speed Enforcement Pilot Projects in Minnesota Work and School Zones
(Center for Transportation Studies, University of Minnesota, 2014-05) Douma, Frank; Munnich, Lee; Garry, Thomas
Studies have shown that automated speed enforcement (ASE), when deployed in certain settings, increases roadway safety. Minnesota is one of the 36 states that do not use ASE. This is despite public opinion polling in Minnesota showing overwhelming public support for ASE in certain locations. This gap in Minnesota between (i) the safety benefits and strong public support for ASE in certain settings and (ii) state policy led to this study. The purpose of the study was to investigate scenarios for an ASE pilot project in Minnesota. Work and school zones were selected as the target deployment location given the polling showing strong public support for ASE there and the experiences in other states showing that ASE is effective in reducing speeding in these areas. The aim of this study was to develop a pilot project blueprint to inform policymakers about the potential for such a project. The study included data and legal analysis, a literature review, and stakeholder engagement.
Test and Evaluate a Bluetooth Based In-Vehicle Message System to Alert Motorists in Work Zones
(Center for Transportation Studies, University of Minnesota, 2019-05) Liao, Chen-Fu
Safe and efficient traffic flow in a work zone is a major concern for transportation agencies. To reduce risky behavior around work zones, we have developed a prototype system to investigate the feasibility of using in-vehicle messages to increase drivers’ awareness of safety-critical and pertinent work zone information. Our previous effort focused on an inexpensive technology based on Bluetooth low energy (BLE) beacons that can be deployed in or ahead of the work zone. A smartphone app, called WorkzoneAlert, was developed to trigger non-distracting, auditory messages in a smartphone mounted in a vehicle within range of the BLE beacons. Messages associated with BLE beacons around the work zone can be updated remotely in real time and thus could provide significantly improved situational awareness about dynamic conditions in work zones, such as awareness of workers on site, changing traffic conditions, or hazards in the environment. We incorporated the recommended in-vehicle message elements and user interface from a human factors study previously conducted by the HumanFirst lab and deployed the in-vehicle work zone information system at three construction sites (CSAH 53, CSAH 112, and MN-65) in the Twin Cities metropolitan area (TCMA). Our field test results indicated that the WorkzoneAlert app is able to reliably detect the BLE beacon placed an average of 127 m away on traffic signs or portable radar speed signs and successfully announce the corresponding message associated with each BLE beacon.
User-centered Smart Traffic Sign Development Study
(Minnesota Department of Transportation, 2023-06) Morris, Nichole L.; Rajamani, Rajesh; Drahos, Bradley A.; Xie, Zhenming; Alexander, Lee; Kessler, William
Flaggers protect workers by providing temporary traffic control and maintaining traffic flow through a work zone. They are often the first line of defense to stop distracted, inattentive, or aggressive motorists from intruding into the work area. This project aims to develop an automated intrusion detection system to alert drivers who are unsafely approaching or entering a flagger-controlled work zone. A human factors user needs assessment found maintenance workers preferred a modified traffic signal to feature the alert system due to flagger risks of being in the roadway and drivers failing to stop and remain stopped when presented with the STOP side of the flagger sign. A modified traffic signal that could be operated using a handheld remote was developed. The low-cost embedded electronics on the traffic signal enabled it to track trajectories of nearby vehicles, detect potential intrusions, and trigger audio-visual warnings to alert the intruding driver. Usability testing in a simulated driving test found poor expectancies and stopping rates of the traffic signal-based alarm system compared to a traditional flagger but did demonstrate evidence that drivers may be less likely to stop and remain stopped with the flagger STOP sign than the red ball indicator of the traffic signal. Furthermore, some drivers corrected their initial stopping error after triggering the auditory alarm of the traffic signal. A follow up test found improved performance with the alert system incorporated into an audiovisual enhanced STOP/SLOW flagger paddle. Testing of the developed sensor system found the system capable of simultaneous multivehicle tracking (including estimation of vehicle position, velocity, and heading) with a range of up to 60 meters and angular azimuth range of 120 degrees and correctly detecting all test intruding vehicles.
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.
Work Zone Mapping and Tag Deployment System
(Center for Transportation Studies, University of Minnesota, 2019-10) Parikh, Gordon; Duhn, Melissa; Loutfi, Andrew; Hourdos, John
Roadway construction is an inevitable part of functional transportation infrastructure. However, work-zone incidents have increased overthe years. This report is the third part of an interdisciplinary project to improve driver safety in work zones. The first component was ahuman factors study, performed by Craig et al. (2017), determining the most effective way to alert drivers to work zones without disrupting driver behavior. The second component, by Liao (2019), sought to determine whether Bluetooth low-energy tags could be deployed in work zones to provide real-time updates to drivers’ mobile phones through an app. The third component, the Statewide Work Zone Information System (SWIS), establishes a real-time database of active work zones from the first advanced warning sign being placed to the time the crews pack up. SWIS uses beacons attached to traffic control devices, called assets, that send messages to a central cloud repository. From there, messages are processed, categorized into Projects, Traffic Control Plans, and Work Zones. SWIS continuouslyupdates based on asset messages it receives. Users can access SWIS through a web interface, to view active, past or future projects, plan aproject, or update existing projects. SWIS provides an online, real-time portal for storing, monitoring, and inspecting work zone traffic-control operations.

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