NJDOT UAS/Drone Procedures Manual and Best Practices for Use in New Jersey

The use of drones at NJDOT has expanded to improve safety and efficiency and save time and money.

The use of drones at NJDOT has expanded to improve safety and efficiency and save time and money.

The NJDOT Knowledge Management Toolbox offers examples of several knowledge sharing practices that have been, or could be, adopted by agency units to retain knowledge in a unit in the face of illness, retirements or transfers to other units at NJDOT.

NJDOT’s Unmanned Aircraft Systems Flight Operations Manual (UASFOM) is an example of knowledge sharing through development of a procedures manual that guides practice within the agency. In 2021, Anil Agrawal, PhD., a Professor of Engineering at The City College of CUNY, completed a research study, NJDOT UAS/Drone Procedures Manual and Best Practices for Use in New Jersey, funded through the NJDOT’s Bureau of Research. The study resulted in the UASFOM that standardizes all aspects of UAS operations for NJDOT’s use, and provides guidance to NJDOT personnel, consultants, and contractors for the inspection, operation, and management of UAS. The document emphasizes maintaining a high level of safety standards in daily flight operations while meeting performance targets.

NJDOT’s Bureau of Aeronautics has used drones to video NJDOT dredging operations, among other applications.

NJDOT’s Bureau of Aeronautics has used drones to video NJDOT dredging operations, among other applications.

Unmanned Aerial Systems (UAS), or drones, were promoted by the Federal Highway Administration (FHWA) as one of the Every Day Counts Round 5 (EDC-5) innovations. In May 2016, the New Jersey Department of Transportation’s Division of Multimodal Services established the Unmanned Aircraft Systems (UAS) Program as a unit within the Bureau of Aeronautics. Under the direction of NJDOT’s UAS Coordinator, Glenn Stott, NJDOT became a national leader in UAS. Mr. Stott retired from the agency in 2021.

NJDOT Bureau of Aeronautics used several funding grants to build the program and purchase equipment and provide training. Integrating UAS in transportation has been the subject of research and field studies to demonstrate the use case for high-mast light pole inspections, traffic incident management and monitoring, dredging and beach replenishment, photogrammetry, bridge inspection, and watershed management, among other topics. UAS has been shown to improve safety, save time and money and increase efficiency. UAS is considered to be institutionalized within NJDOT.

An example Risk Management Worksheet is one of several forms described in the Procedures Manual.

An example Risk Management Worksheet is one of several forms described in the Procedures Manual.

The procedures manual provides comprehensive guidance for UAS missions from planning to debriefing. The manual presents NJ’s laws and regulations affecting UAS operations, discusses NJDOT’s safety management system and risk management approach, established best practices, the agency’s three-phase training program, and incident reporting. The manual also provides NJDOT’s UAS forms needed for documentation and to ensure compliance with Federal Aviation Administration (FAA) regulations. The manual is intended to be a “living document” to incorporate changes as experience grows with UAS within the agency.

A procedures manual is one way to counter the loss of expertise and institutional knowledge when employees retire or transfer. A manual can build and sustain knowledge within the agency to ensure continuity of operations.

The UASFOM can be found in the Knowledge Management Toolbox. The Final Report and Technical Brief for the Research can be accessed here.

Share Your Ideas on the NJ Transportation Research Ideas Portal!

The New Jersey Department of Transportation’s (NJDOT) Bureau of Research invites you to share your ideas on the NJ Transportation Research Ideas Portal.

We are asking NJDOT’s research customers and other transportation stakeholders to propose research ideas for the NJDOT Research Program. Join us in finding workable solutions to problems that affect the safety, accessibility, and mobility of New Jersey’s residents, workers, visitors and businesses.

REGISTER TO PARTICIPATE.  Once you are registered, you may submit ideas at any time.  If you registered last year, you do not need to register again.

HOW DO I SUBMIT AN IDEA?  Only registered participants can log in to submit a new idea or vote on other ideas to show your support. Register at the NJ Transportation Research Ideas website welcome page here:  https://njdottechtransfer.ideascale.com/

NEXT ROUND OF RESEARCH.  Please submit your research ideas no later than December 31, 2021 for the next round of research RFPs. The NJDOT Research Oversight Committee (ROC) will prioritize research ideas after this date, and high priority research needs will be posted for proposals.

Questions about how to register?
Email: ideas@njdottechtransfer.net

For more information about NJDOT Bureau of Research, visit our website: https://www.state.nj.us/transportation/business/research/

Or contact us:  Bureau.Research@dot.nj.gov or (609) 963-2242

Research Spotlight: Evaluating the Pedestrian Hybrid Beacon’s Effectiveness:  A Case Study in New Jersey

A Pedestrian Hybrid Beacon (PHB) is a signalized, pedestrian-activated device designed to increase crossing safety. A recent study conducted by the New Jersey Bicycle and Pedestrian Resource Center (BPRC), funded by NJDOT, examined the efficacy and public awareness of PHBs in New Jersey. The authors, researchers from Rowan and Rutgers universities, found a persistent need to better educate motorists and pedestrians in New Jersey on the PHB and its phases.

The five phases Pedestrian Hybrid Beacon’s (PHB) operations

The five phases Pedestrian Hybrid Beacon’s (PHB) operations

Pedestrian Hybrid Beacons are one of FHWA’s seven Safe Transportation for Every Pedestrian (STEP) countermeasures, proven methods of reducing pedestrian collisions. STEP was promoted through multiple rounds of the FHWA’s Every Day Counts (EDC) Program. A PHB is typically placed to improve pedestrian safety at uncontrolled and mid-block crossings, in locations with high pedestrian demand and wide roadways. The treatment consists of two signal arms on each side, with pedestrian “push buttons” and a crosswalk. The PHB operates in five phases. In the first, the PHB’s signal is off. The second phase begins when a pedestrian activates it by pressing a button, prompting the signal to flash a yellow light. Then, for the third phase, the flashing transitions to a solid yellow light, communicating to drivers that they should prepare to stop. Then the light turns red, and, in the fourth phase, the pedestrian signal changes to “Walk.” After an interval, the fifth phase begins: the pedestrian signal displays a countdown timer, and the traffic signal flashes alternating red lights, telling drivers to stop and that they may proceed if the crosswalk is clear.

The study’s literature review found multiple examples of prior research demonstrating the efficacy of PHBs. In the case of Tucson, Arizona, where one of the first PHBs was deployed in the United States, one study found a 69 percent decrease in pedestrian-related crashes in the signal area. Another analysis in Tucson found a 97 percent yielding rate from drivers at PHB-equipped crossings. One of the chief findings from the literature review was that PHB signal evaluations were lacking in New Jersey. Thus, researchers aimed to more systematically analyze PHBs in the state.

The authors found ten implemented examples of PHBs throughout the state, from Bergen County to Atlantic County. For more in-depth research, they selected signals in three different community types (urban, suburban, and campus area), in Morristown, Medford, and New Brunswick, New Jersey, to undergo video analysis.

The five phases Pedestrian Hybrid Beacon’s (PHB) operations

The five phases Pedestrian Hybrid Beacon’s (PHB) operations

One commonality observed in all three locations was an apparent confusion for motorists concerning the fifth phase, in which the signal flashes red, indicating that drivers should stop and then proceed with caution. In New Brunswick, 100 percent of observed motorists remained stopped, even after the intersection had been cleared. In Morristown, the vast majority of pedestrians (91.3%) failed to use the PHB during the morning period, and also failed to do so in the evening (83%). The authors attribute such behavior to the PHB timing being linked to two nearby traffic signals, contributing to extra delay after the crossing button has been pressed. When inconvenient, it seems, pedestrians may opt to cross on their own.

To better understand the familiarity of pedestrians and motorists in New Jersey with PHBs, the researchers designed an online survey that was sent to 79,567 randomly selected email addresses from 30 communities across the state. While respondents indicated some confusion as to how PHBs functioned, a plurality indicated that they would be very likely or somewhat likely to support  implementation in their own community. A majority of respondents (85.9%) reported that they had never heard of PHBs, and later indicated that completing the short survey had increased their knowledge of the safety treatment, showing the potential benefit of more public education about their functionality.

The report concludes by stating that while PHBs are proven to be effective at increasing pedestrian crossing safety, a lack of public awareness on the part of both drivers and pedestrians currently limits the effectiveness of these devices. The researchers suggest updating the New Jersey Motor Vehicle Commission’s Driver’s Handbook to include the PHB, and to differentiate the flashing red signals at a PHB where the driver must yield and then proceed if the crosswalk is clear, from the flashing red signals at railroad crossings where the driver is required to stop and remain stopped. This addition could be complemented with a public education campaign to teach pedestrians and drivers about the intricacies of Pedestrian Hybrid Beacons.

The New Jersey Bicycle and Pedestrian Resource Center (BPRC) works to promote a safer and more accessible walking and bicycling environment in the state. The Center, located at the Alan M. Voorhees Transportation Center at Rutgers, is supported by NJDOT through funding from FHWA. Further information technical assistance, resources for Complete Streets, and current research is available on the BPRC’s website.


Resources

Federal Highway Administration. Pedestrian Hybrid Beacons. Federal Highway Administration. https://safety.fhwa.dot.gov/provencountermeasures/ped_hybrid_beacon/

New Jersey Bicycle and Pedestrian Resource Center. (2020). Evaluating the Pedestrian Hybrid Beacon’s Effectiveness: A Case Study in New Jersey. New Jersey Bicycle and Pedestrian Resource Center. http://njbikeped.org/portfolio/evaluating-pedestrian-hybrid-beacons-effectiveness/

NJDOT Tech Transfer. (2019). What is a Pedestrian Hybrid Beacon? NJDOT Tech Transfer. Video. https://www.njdottechtransfer.net/2019/09/27/njdot-safety-countermeasures-videos/

NJDOT Tech Transfer. (2020). STEP-Aligned HAWK Signal Installed in Bergen County. NJDOT Tech Transfer. https://www.njdottechtransfer.net/2020/03/20/step-aligned-hawk-signal-installed-in-bergen-county/

 

Research to Implementation: Design and Evaluation of Scour for Bridges Using HEC-18

This Research to Implementation video presents an example of NJDOT-sponsored research and the effect such research has in addressing transportation-related issues within the State.

Bridge scour is the removal of sediment such as sand and gravel from around non-tidal bridge substructures and supports caused by swiftly moving water. This water can scoop out ​scour holes​, compromising the integrity of a structure. Understanding the extent of bridge damage and prioritizing the order of repair is critical to maintaining safe bridges.

With the support of NJDOT's Bureau of Research, researchers developed the NJ-specific Scour Evaluation Model (SEM) to prioritize bridges for repair. The SEM model was determined to be effective and is now approved by FHWA and NJDOT to evaluate scour risk. The project included training of consultants to encourage the expanded use of the SEM model in NJ.

The video promotes the benefits of funded research to increase the safety of the traveling public, reduce costs, and increase efficiency.

Research to Implementation: Environmental Impacts of Reclaimed Asphalt Pavement

This Research to Implementation video presents an example of NJDOT-sponsored research and the effect such research has in addressing transportation-related issues within the State.

Reclaimed Asphalt Pavement (RAP) is material gathered through the milling and removal of existing pavement surfaces. In New Jersey, reuse of this material is restricted to inclusion in new asphalt pavements. NJDOT's Bureau of Research supported a study that explored the environmental impacts associated with reuse of RAP in unbound applications.

The video summarizes the research and the resulting recommendations that have influenced legislation and helped frame discussions among various stakeholders concerning the beneficial uses of RAP.

Share Your Ideas on the NJ Transportation Research Ideas Portal!

The New Jersey Department of Transportation’s (NJDOT) Bureau of Research invites you to share your ideas on the NJ Transportation Research Ideas Portal.

We are asking NJDOT’s research customers and other transportation stakeholders to propose research ideas for the NJDOT Research Program. Join us in finding workable solutions to problems that affect the safety, accessibility, and mobility of New Jersey’s residents, workers, visitors and businesses.

REGISTER TO PARTICIPATE.  Once you are registered, you may submit ideas at any time.  If you registered last year, you do not need to register again.

HOW DO I SUBMIT AN IDEA?  Only registered participants can log in to submit a new idea or vote on other ideas to show your support. Register at the NJ Transportation Research Ideas website welcome page here:  https://njdottechtransfer.ideascale.com/

NEXT ROUND OF RESEARCH.  Please submit your research ideas no later than December 31, 2020 for the next round of research RFPs. The NJDOT Research Oversight Committee (ROC) will prioritize research ideas after this date, and high priority research needs will be posted for proposals.

Questions about how to register?
Email: ideas@njdottechtransfer.net

For more information about NJDOT Bureau of Research, visit our website: https://www.state.nj.us/transportation/business/research/

Or contact us:  Bureau.Research@dot.nj.gov or (609) 963-2242

Development of Real-Time Traffic Signal Performance Measurement System

Adaptive Signal Control Technology (ASCT) is a smart traffic signal technology that adjusts timing of traffic signals to accommodate changing traffic patterns and reduce congestion. NJDOT recently deployed this technology in select corridors and required a set of metrics to gauge functionality and effectiveness in easing traffic congestion and reliability. However, the monitoring and assessment of the ASCT performance at arterial corridors has been a time-consuming process.

The Automated Traffic Signal Performance Measures system (ATSPMs) developed by Utah DOT is one of the widely-used platforms for traffic signal performance monitoring with a large suite of performance metrics. One limitation of the existing ATSPM platform is its dependency on high-resolution controllers and the need to set up hardware and software at each individual intersection. Upgrading the existing controllers and reconfiguring the hardware and software at each intersection requires significant investment of funding and labor hours.

Recently completed research funded by the New Jersey Department of Transportation’s Bureau of Research mobilized researchers from Rutgers University, The College of New Jersey (TCNJ), and Rowan University to assist in advancing the goal of establishing automated traffic signal performance measures. The goals of the needed research were to develop a prototype Automated Traffic Signal Performance Measures platform for ASCT systems. The main focus was how to take advantage of the centrally-stored signal event and detector data of ASCT systems to generate the ATSPM performance metrics without intersection-level hardware or software deployment.

The study’s primary objectives were to examine: 1) how to utilize existing field data and equipment to establish Signal Performance Measures (SPMs) for real-time monitoring; and 2) identify what additional data and equipment may be employed to generate additional SPMs while automating the real-time traffic signal monitoring process. This research is especially important for New Jersey (NJ) with the deployment of ATSPM and the establishment of NJDOT’s Arterial Management Center (AMC).

Background

At present, NJDOT maintains a traffic signal system comprised of many types of equipment that affect signal performance, including different signal configurations and vehicle detection devices. Older equipment and ineffective detection technologies make real-time traffic signal monitoring quite difficult to implement across the state. With the implementation of more centrally-controlled traffic signal systems and the Department’s Arterial Management Center (the central control for remotely monitoring these signals) coming online, NJDOT needed standards to assure that the signals would operate properly and ease traffic congestion, and that the signals could be monitored remotely in real-time effectively.

ATSPMs are promoted by FHWA (Federal Highway Administration) as an EDC-4 (Every Day Counts 4) initiative. The use of ATSPMs has important foreseeable benefits:

  • Increased Safety. A shift to proactive operations and maintenance practices can improve safety by reducing the traffic congestion that results from poor and outdated signal timing.
  • Targeted Maintenance. ATSPMs provide the actionable information needed to deliver high-quality service to customers, with significant cost savings to agencies.
  • Improved Operations. Active monitoring of signalized intersection performance lets agencies address problems before they become complaints.
  • Improved Traffic Signal Timing and Optimization Policies. Agencies are able to adjust traffic signal timing parameters based on quantitative data without requiring a robust data collection and modeling process.
Research Approach

The research team recognized that the deployment of various adaptive traffic control systems such as InSync and SCATS systems on major NJ corridors and networks improved the capability for building real-time performance measures. The study included: a review of the literature and best practices; several stakeholder meetings; and recommendations and development of performance metrics, system architectures, data management, and strategies for deploying ATSPM systems using existing and planned NJDOT arterial infrastructure and technologies.

Figure 1: An Example real-time performance monitoring on County Road 541 and Irwick Road, Burlington County, NJ

Figure 1. An Example real-time performance monitoring on County Road 541 and Irwick Road, Burlington County, NJ

The researchers first conducted a literature review to identify examples of existing Signal Performance Measurement (SPM) systems to help inform the development of ATSPMs. The researchers described several exemplary initiatives, including the following:

  • In 2013, the Utah Department of Transportation’s (UDOT) SPM Platform was named an American Association of State Highway and Transportation Officials (AASHTO) Innovation Initiative. Deployed across the state, the system allows UDOT to monitor and manage signal operations for all signals maintained by the agency while aiding in more efficient travel flows along corridors.
  • From 2006 to 2013, the Indiana Department of Transportation (INDOT), with Purdue University, established a testbed of signal performance measures. INDOT developed a common platform for collecting real-time signal data, which became the foundation for AASHTO’s Innovation Initiative on Signal Performance Measures. This performance system has now been deployed at more than 3,000 intersections across the country.
  • Researchers at The College of New Jersey have established a signal performance measurements testbed using Burlington County’s centralized traffic signal management system. Traffic signal data collected along County Route 541 has been used to generate real-time performance measures and identify infrastructure improvements that could advance NJDOT’s ability to use real-time SPMs. An example of the existing real-time performance monitoring for Irwick Road and CR541 in Westhampton, NJ in Burlington County is shown in Figure 1.
  • Many state or local agencies including Pennsylvania DOT, Michigan DOT, New Jersey DOT, Lake County (Illinois), and Maricopa County (Arizona), etc., are actively incorporating ATSPMs into their traffic management and operation strategies. Lessons learned from implementation of ATSPMs from different agencies revealed that ATSPMs are critical to ATCS.

The research team organized and facilitated targeted stakeholder meetings. These meetings confirmed that stakeholders were not currently able to perform efficient real-time post-processing of the existing available data.  Through the meetings, the research team was able to scope more deeply into the type of performance measurements that were feasible and what could be done with the collected information.  Stakeholders also conveyed that the total number of operating adaptive signal intersections would more than double in the near-term future, making the need to efficiently process and leverage data from adaptive systems a more pressing concern. The discussions further confirmed that the big question for study was how to best leverage these adaptive systems to evaluate and manage future corridors.

Figure 2. Corridors where NJDOT has deployed ASCT systems; red denotes full operation, yellow denotes under construction, and blue denotes concept development

Figure 2. Corridors where NJDOT has deployed ASCT systems; red denotes full operation, yellow denotes under construction, and blue denotes concept development

The research team sought to better understand the inventory of NJDOT’s existing and planned ASCT systems. In 2019, New Jersey had over 2,500 NJDOT-maintained signals, but only 76 signals were on Adaptive Traffic Signal Systems.  In addition to the existing five corridors and the district in which ASCT systems had been deployed, 3 corridors were under construction and/or in final design and another 11 corridors were in the concept development phase for future ASCT installation at the time of the study (see Figure 2).

The research team visited the state’s Arterial Management Center (AMC) and investigated several signal performance systems – specifically, the Sydney Coordinated Adaptive Traffic System (SCATS), Rhythm Engineering’s InSync, and the Transportation Operations Coordinating Committee’s (TRANSCOM) real-time data feed – to better understand their interfaces, different types of detectors and their availability.

Figure 3. System Operation Data Flow Diagram

Figure 3. System Operation Data Flow Diagram

The research team designed an automated traffic signal performance measurement system (ATSPM) based on existing ATSPM open-source software to develop an economically justifiable ATSPM for arterial traffic management in New Jersey.  The entire system operates as shown in Figure 3. The high-resolution controller belonging to existing infrastructure is connected to an AMC at each signalized intersection. The controller event log file contains signal state data that is sent to an AMC database. The research team’s program automatically retrieves these data logs and translates the unprocessed data into a standard event code. The converted event file is inserted into an ATSPM database and the ATSPM software can generate signal performance metrics and produce visualizations to support performance-based maintenance and operations by traffic engineers.

Key Research and Implementation Activities

The research team successfully created a bench test of the ATSPM system based on data collected from high-resolution data from adaptive signal control systems including 13 SCATS locations on NJ Route 18 and 2 InSync locations on US Route 1. As a result of the testing, the research team successfully assembled a prototype for automated traffic signal performance measures in New Jersey.

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Key research activities from the project are as follows:

  • Create Inventory of Existing NJDOT Arterial Management System: The team investigated several signal performance systems including InSync, SCATS, and TRANSCOM fusion application interfaces and different types of detectors and their availability. The team also conducted intensive review of state-of-the-art-and-practice of ATSPM system and identified ways of migrating the system to NJ.
  • Identify Performance Metrics and Measurement Methods for NJDOT ATSPM System: The team conducted a comprehensive review of SPMs built into an ATSPM system. The team investigated and customized SPMs that can be generated by NJDOT detector and travel time data.
  • Develop System Architecture and Concept of Operations for NJDOT ATSPM System and Established a Bench Test of ATSPM Located on TCNJ’s Campus: To leverage the existing ATCS system, the team developed a signal event conversion program to translate existing SCATS and InSync history log file to an event code that can be recognized by ATSPM. The detailed metrics are summarized in the figures to the right.
  • Prepare Real-Time Traffic Signal Data Management Guidelines: The research team created data management guidelines and a manual for data processing. The team validated the outputs through a comprehensive process. The team also completed a test to automatically connect to an ATSPM database using a VPN and MSSQL database management system.
  • Develop Deployment Strategies Considering Existing, Planned, and Future Systems/ Conduct Case Studies of System Deployment: The team initiated the pulling of one-month of data into their platform for the ATSPM. Large scale deployment of this system was expected to be conducted as part of Phase II research.

The research team observed that ATSPMs have distinct advantages over traditional traffic signal monitoring and the accompanying management process. The systems help shorten feedback loops with easier data collection and signal performance comparisons to enable before and after timing adjustments.

Future Work

In the first phase of the research project, the research team developed a software toolbox, NJDOT ATSPM 1.0.  The toolbox can convert the event output data from SCATS and InSync ATSC Systems into event data that can be processed by the ATSPM platform. The primary accomplishment was to integrate ATSPMs with existing ATCS from the centralized management console, instead of configuring at each controlled intersection on field. The proposed system bridges the gap between increasingly deployed ATSC and emerging ATSPMs without investment on new controllers. The effect of this research was validated on two selected corridors. NJDOT arterial management operators are able to use the ATSPM platform to generate key performance metrics and conduct system analysis for NJDOT’s ATSC corridors.

While the initial deployment and analysis was successful, it was limited in its scope. Phase II of the research involves the development and deployment of a significantly-enhanced version of the original toolbox, NJDOT ATSPM 2.0, along with a pilot study on the integration of ATSC controllers with Connected Autonomous Vehicle (CAV) technologies.

The research team will work with NJDOT to identify and add new performance metrics to generate additional Signal Performance Measures. The team can incorporate proprietary data from traveler information providers (e.g. INRIX and HERE) to generate other performance metrics such as queue/wait time, degree of saturation, predicted volumes, etc., and incorporate them into the NJDOT ATSPM platform. The team will also conduct pilot testing on the integration of Connected and Automated Vehicle (CAV), Roadside Units (RSU), On Board Unit (OBU) with the existing and planned NJDOT ATSC systems.

This developed ATSPM system from Phase II will bridge the gap between collected traffic data (e.g., signal controller data, detector data, and historical data) and needed performance information for decision-making. Phase II research is underway with an expected completion by November 2021.

Relationship to Strategic Goals

The development of RT-SPMs and the adapting and deployment of ATSPM with existing NJ ATSC systems is aligned with the FHWA EDC (Every Day Counts) Initiative to promote the rapid deployment of proven innovations. NJDOT ATSPM 2.0 will help meet the strategic EDC goal to accelerate the deployment of ATSPMs on existing and planned arterial corridors to reduce crashes, injuries, and fatalities, optimize mobility and enhance the quality of life.

The Phase II research supports the state initiative on advancing policy and testing of CAV technologies in New Jersey. The outcome of the project will be reported to NJDOT which is part of the New Jersey Advanced Autonomous Vehicle Task Force to make recommendations on laws, regulations and guidance to safely integrate advanced autonomous vehicle testing on the State’s highways, streets, and roads.


Resources

McVeigh, Kelly. (2019). Automated Traffic Signal Performance Measures.  Presentation at NJ STIC May 7th, 2019 Meeting.

Jin, P. J., Zhang, T., Brennan Jr, T. M., & Jalayer, M. (2019). Real-Time Signal Performance Measurement (RT-SPM) (No. FHWA NJ-2019-002).  Retrieved at: https://www.njdottechtransfer.net/wp-content/uploads/2020/01/FHWA-NJ-2019-002.pdf

Jin, P. J., Zhang, T., Brennan Jr, T. M., & Jalayer, M. (2019). Real-Time Signal Performance Measurement (RT-SPM) – Technical Brief Retrieved at: https://www.njdottechtransfer.net/wp-content/uploads/2020/01/FHWA-NJ-2019-002-TBrev.pdf

Zhang T., Jin P., Brennan, T., McVeigh, K. and Jalayer, M, Automating the Traffic Signal Performance Measures for Adaptive Traffic Signal Control System. ITS World Congress. 2020.

Spotlight: New Technology Evaluations

The New Technologies and Products (NTP) Unit in NJDOT’s Division of Bridge Engineering and Infrastructure Management reviews and evaluates new technologies and products submitted by manufacturers, vendors and suppliers. The unit is currently evaluating over 50 products for possible use at NJDOT to address needs related to safety, pavement, drainage, bridges and structures, among other categories.

NJDOT defines a new technology as “any product, process, or material used in the construction and maintenance of roadways and bridges that is not covered by existing NJDOT standard specifications or construction details, thereby requiring a formal evaluation for approval.” Products may receive a formal evaluation if they are finished and marketed, and address high priority needs.

The unit maintains the New Technologies and Products database of tested products from 2002 to the present. The database displays the category, the name of the product with a link to the product webpage, the company and the status of the evaluation. The NTP database status code legend is available on the NJDOT New Technology Evaluations webpage. Products may be actively undergoing testing, in a demonstration phase, or specification development phase, or in other stages of evaluation.

If, through the evaluation process, a technology or product is found acceptable for use on NJDOT projects, development and implementation of a standard specification, construction detail, or design guideline is still needed through a baseline document change.

Evaluation typically takes two to three years, although technical information and testing data from other testing agencies may expedite the process. Proposals for use of a new technology on a specific project, and recurrent use of an alternate or non-standard item on several projects, can lead to acceptance as a standard item.

 

 

Evaluating New Jersey’s Use of Raised Pavement Markers for Roadway Safety

In the United States, data has shown that more than a third of fatal crashes on two-lane undivided highways and 27 percent of fatal crashes on four-lane divided highways occur in dark, unlighted conditions. Raised Pavement Markers (RPMs) are a common device deployed for roadway safety around the world since the 1930s. RPMs are delineation devices used to improve preview distances and provide guidance for drivers in inclement weather and low-light conditions. There are two main types of RPMs, ones that can be used with snow plows and ones that cannot.

While most states install RPMs selectively based on particular locational characteristics of the roadways, New Jersey uses RPMs along all centerlines (solid and skip), regardless of traffic volume, roadway geometry, or roadway classification. The extensive use of RPMs in New Jersey has raised interest in understanding 1) whether this significant investment generates variant safety benefits at different locations; 2) whether there are alternatives or modifications to the existing RPMs; and 3) how to optimize the installation, monitoring, and maintenance of RPMs and their promising alternatives in order to attain a more cost-effective safety improvement.

The selected team from Rutgers University and Rensselaer Polytechnic Institute employed four distinct methods to address these research questions. The first was to conduct a literature review to inform the development of a methodological framework for quantifying the safety and cost-effectiveness of RPMs and their alternatives, based on specific road and traffic characteristics. Second, the researchers developed a luminance measurement method to compare the luminance of RPMs to different markers’ ability to inform drivers of road lines. Luminance measurement is defined as “the amount of visible light leaving a point on a surface in a given direction” (“Lighting Design Glossary”). Third, the group conducted a survey of other state DOTs practices and their guidelines for installation, including alternatives used. Lastly, the researchers developed a computer-aided decision support tool to calculate the life cycle costs of RPMs and their alternatives. Different alternatives were considered throughout the study, including various forms of rumble strips, preformed tape, and delineators.

The researchers came to several findings that provided insight into NJDOT’s current use and potential future research opportunities. The literature review of previous studies was inconclusive, with no consensus on whether RPMs affect the crash rate on roadways, with past research showing both negative and positive safety changes post-installation.

RPM samples used for measurements in the luminance tests. Photo Source: Xiang et al.

The survey of state DOTs yielded 22 responses from states throughout all regions of the country. The survey had two main sections, “RPM Installation” and “RPM Inspection and Maintenance”. No consensus or clear pattern was found among the states in terms of practices for installation, inspection, maintenance, and alternatives used. However, the researchers found that other state DOTs were more selective than New Jersey in choosing RPM installation sites based on traffic volume, accident history, and weather conditions.

To quantify the contribution that RPMs make towards safety outcomes on New Jersey roads, researchers compared the safety performance of county roads since unlike state roads, some county roads do not have RPMs installed. The researchers found that county roads with RPMs had a 19 percent lower crash rate than county roads without RPMs. The most significant decreases in crash rates occurred in nighttime, wet weather conditions, providing insight into the conditions that RPMs may be most effective.

In the lab luminance study, the team tested samples of new and used RPMs, along with alternatives such as wet pavement reflective tape and channel-mounted delineators to determine how far away drivers could see the markers in nighttime conditions. The average lifecycle for RPMs is 6 years, with a maintenance cycle of 2-3 years. Used RPMs showed a 20-30 percent decrease in luminance than new RPMs, but that did not translate to decreased visual performance.

Finally, the team created a computer-aided decision support tool to evaluate and compare the life cycle cost of RPMs and alternatives, based on specific operational characteristics. Decision-makers can couple information on safety benefits for each device with the total cost for per unit crash reduction from the tool to compare the value of the investment. The tool accounts for installation cost, traffic control cost, traffic delay cost, inspection cost, maintenance and repair cost, as well as the liability cost associated with incidents due to damaged RPMs or alternatives.

The research team also suggested several areas for future study for advancing NJDOT’s understanding of RPMs and their alternatives. The researchers recommended a study of optimal spacing or degree of continuous delineation that drivers need for safety. In the luminance study, all the devices had high visual performance despite variance in luminance when tested at a 100-meter viewing distance. However, the researchers noted, additional study was needed to see how the differences in luminance could affect visual performance at the threshold visibility distance (when the devices can be first seen). The results could help identify which device gives drivers more time and distance, resulting in potential reduction in nighttime crashes.

Rumble Strips. Photo Source: FHWA.

Lastly, one of the alternatives frequently mentioned throughout the study is rumble strips, which are used on roadways to create a noise and vibration to alert a driver when they leave their lane. When painted with retroflective coating to increase visibility, they are called rumble stripes (FHWA 2019). The researchers explained that rumble strips have not been studied in regard to safety effectiveness in New Jersey due to data limitations, making it a potential future research area.

New Jersey is in a unique position compared to other states with its comprehensive use of RPMs on state roadways. The researchers were able to provide valuable information to NJDOT, including a methodological framework for the department moving forward to quantify the safety effectiveness of RPMs and their alternatives and a computer-aided decision support tool to estimate life cycle cost. With this information and targeted areas for future research, NJDOT can aim to make cost-effective investments that will improve roadway safety.

Resources:

FHWA. “Rumble Strips and Rumble Stripes.” FHWA. April 1, 2019. https://safety.fhwa.dot.gov/roadway_dept/pavement/rumble_strips/general-information.cfm.

“Lighting Design Glossary.” Lighting Design and Simulation Knowledgebase. https://www.schorsch.com/en/kbase/glossary/luminance.html.

Liu, Xiang, John Bullough, Liwen Tian, Shan Jiang, and Mohsen Jafari. Evaluation of Raised Pavement Markers, Final Report. July 2018.
https://www.njdottechtransfer.net/wp-content/uploads/2019/04/FHWA-NJ-2018-004.pdf

Liu, Xiang, John Bullough, Liwen Tian, Shan Jiang, and Mohsen Jafari. “Technical Brief: Evaluation of Raised Pavement Markers.” July 2018.
https://www.njdottechtransfer.net/wp-content/uploads/2019/04/FHWA-NJ-2018-004-TB.pdf

 

New Protocol for Accepting Over-Coating Paint on Steel

The Research Advisory Committee of the American Association of State Highway and Transportation Officials (AASHTO) selected an NJDOT project as one of 16 high-value research projects for 2019 in the category of Smart Maintenance and Preservation. Researchers from Rutgers’ Center for Advanced Infrastructure and Transportation, Perumalsamy Balaguru, Husam Najm, and David Caronia, developed a new testing method for the durability of paint overcoat on steel structures, such as bridges.

NJDOT received AASHTO’s Research “Sweet Sixteen” 2019 award for innovative research establishing a new protocol for durability testing of structural steel overcoats.

On behalf of the NJDOT Bureau of Research, Giri Venkiteela, Research Project Manager, delivered a poster presentation and Pragna Shah, Research Project Manager, accepted the AASHTO award at the 2019 National RAC and TRB State Representatives Meeting in Santa Fe, New Mexico in July 2019.

The new protocol allows for reduced testing time from previous methods, identifies durable coatings, simulates field performance, and has significant potential for adoption in accepting all new coatings. This new protocol will save money and reduce environmental pollution resulting from degraded coatings.  The innovative research for this new protocol is described in the Final Report and Technical Brief.