Developing and Simulating a Communication Plan for Mitigation of Secondary Crashes: Leveraging Connected Vehicle Technologies

The Federal Highway Administration (FHWA) has identified secondary crashes (SCs) on United States (US) highways as one of the core transportation issues that needs to be addressed. These crashes contribute to increased property damage, injuries, and fatalities and a decline in traffic flow conditions on freeways and adjacent arterials. The purpose of this study was to 1) propose a communication plan that leverages connected vehicle (CV) technologies to increase awareness to road users to target the mitigation of SCs, and 2) to evaluate the potential benefits of the proposed communication plan with CV technologies in alleviating SCs. This study used VISSIM microscopic software to model a freeway road segment on Florida’s Turnpike system and Lyons Road, a parallel arterial. The software was used to replicate the proposed communication plan and CV applications to issue advisories, such as speed, lane-change, or detour advisory to drivers during an incident. A safety evaluation was performed using the Surrogate Safety Assessment Model (SSAM) software by importing trajectory files from VISSIM to analyze generated traffic conflicts. The change in the number of simulated conflicts was used to evaluate the mitigation of SCs. The results showed significant safety benefits using the proposed communication plan with CV technologies. A conflict reduction of up to 98% was observed with full penetration of CVs at low traffic volume. Statistical analysis indicated that different penetration rates of CVs were required to achieve significant safety benefits depending on the analyzed scenario, i.e., traffic volume, number of lanes closed, side of the road the lane is closed, and dissemination of detour advisory

Methods for Utilizing Connected Vehicle Data in Support of Traffic Bottleneck Management

The decision to select the best Intelligent Transportation System (ITS) technologies from available options has always been a challenging task. The availability of connected vehicle/automated vehicle (CV/AV) technologies in the near future is expected to add to the complexity of the ITS investment decision-making process. The goal of this research is to develop a multi-criteria decision-making analysis (MCDA) framework to support traffic agencies’ decision-making process with consideration of CV/AV technologies. The decision to select between technology alternatives is based on identified performance measures and criteria, and constraints associated with each technology. Methods inspired by the literature were developed for incident/bottleneck detection and back-of-queue (BOQ) estimation and warning based on connected vehicle (CV) technologies. The mobility benefits of incident/bottleneck detection with different technologies were assessed using microscopic simulation. The performance of technology alternatives was assessed using simulated CV and traffic detector data in a microscopic simulation environment to be used in the proposed MCDA method for the purpose of alternative selection. In addition to assessing performance measures, there are a number of constraints and risks that need to be assessed in the alternative selection process. Traditional alternative analyses based on deterministic return on investment analysis are unable to capture the risks and uncertainties associated with the investment problem. This research utilizes a combination of a stochastic return on investment and a multi-criteria decision analysis method referred to as the Analytical Hierarchy Process (AHP) to select between ITS deployment alternatives considering emerging technologies. The approach is applied to an ITS investment case study to support freeway bottleneck management. The results of this dissertation indicate that utilizing CV data for freeway segments is significantly more cost-effective than using point detectors in detecting incidents and providing travel time estimates one year after CV technology becomes mandatory for all new vehicles and for corridors with moderate to heavy traffic. However, for corridors with light, there is a probability of CV deployment not being effective in the first few years due to low measurement reliability of travel times and high latency of incident detection, associated with smaller sample sizes of the collected data

Effect of dynamic route guidance on urban traffic network under Connected Vehicle environment

Although Connected Vehicle technology is developing rapidly, connected vehicles (CV) are going to mix with the traditional vehicles (i.e., non-connected vehicles) for a long time. The effects of deploying CV on urban traffic systems are actually not clear. The main objective of this study is to evaluate the potential effects of route guidance under connected vehicle environment on an urban traffic network in terms of traffic mobility and safety. Microscopic simulation approach is used to conduct CV environment simulation and the rolling horizon approach is used for information updating among the connected vehicles. Meanwhile, driving behavior is modeled through aggressiveness and awareness of drivers. Traffic mobility for the road network was measured by average trip time and average vehicle trip speed. A surrogate measure, i.e., the time-to-collision involved incident rate for one kilometer driven, was used to assess the safety of the road network. Based on a real urban traffic network, the impacts of market penetration levels of connected vehicles and information updating intervals were studied. Simulation results showed that market penetration level of connected vehicles has little impact on the mobility and safety of road network. In addition, according to the simulation conducted in this paper, shorter updating interval is shown to be likely to lead to better mobility, while the safety of road network is likely to decline, under the assumptions embraced in the simulation. By contrast, the simulation also showed that longer updating interval is likely to lead to better safety and decreased mobility

Performance Evaluation of Connected Vehicle (CV) and Transportation Systems Management and Operations (TSM&O) Projects in Florida

BDV29-977-64Connected vehicle (CV) technologies and Transportation Systems Management and Operations (TSM&O) strategies are increasingly being considered by transportation agencies to improve the safety and mobility of the transportation network. To fully understand the potential benefits of CV and TSM&O initiatives, it is crucial to not only identify the performance measures used to evaluate the progress of each initiative, but also to estimate the benefit-to-cost (B/C) ratios to justify the funding requests associated with implementing these technologies and strategies. The primary goal of this research was to assist the Florida Department of Transportation (FDOT) in developing approaches to evaluate the performance of CV projects and current TSM&O strategies being deployed, including the Rapid Incident Scene Clearance (RISC) program, the Road Ranger Service Patrol (RRSP) program, and the Smart Work Zone (SWZ) TSM&O strategies. A comprehensive review of the existing body of literature was conducted to identify the quantitative and qualitative performance measures and metrics that are being considered in evaluating the performance of CV deployments and TSM&O strategies. B/C analyses were conducted to quantify the mobility and safety benefits associated with implementing the RISC and RRSP programs. Results indicate that for every dollar spent on the RISC program, $5.78 is returned in secondary crash savings, and$1.20 is returned in incident-related traffic delay savings. For every dollar spent on the RRSP program, $5.15 is returned in secondary crash savings, and$7.44 is returned in incident-related traffic delay savings. The study also discussed the potential safety and mobility benefits of Smart Work Zone (SWZ) technologies. Performance criteria and evaluation metrics were also developed for the different stages of the CV project development process (i.e., pre-project phase, planning phase, design-deploy-test phase, and the operations & maintenance phase). The performance criteria of two CV deployments in Florida (Gainesville Signal Phase and Timing (SPaT) Project and I-4 Florida\u2019s Regional Advanced Mobility Elements (I-4 FRAME) Project) were also reviewed. Findings from this research offer guidance in evaluating the effectiveness of CV and TSM&O initiatives. Evaluation criteria and approaches presented in this report can better prepare FDOT for deployments

Connected Vehicle Technology: User and System Performance Characteristics

The emerging connected vehicle (CV) technology plays a promising role in providing more operable and safer transportation environments. Yet, many questions remain unanswered as to how various user and system characteristics of CV-enabled networks can shape the successful implementation of the technology to maximize the return on investment. This research attempts to capture the effect of multiple factors such as traffic density, market penetration, and transmission range on the communication stability and overall network performance by developing a new CONnectivity ROBustness (CONROB) model. The model was tested with data collected from microscopic simulation of a 195 sq-mile traffic network and showed a potential to capture the effect of such factors on the communication stability in CV environments. The information exchanged among CVs can also be used to estimate traffic conditions in real time by invoking the probe vehicle feature of CV technology. Since factors affecting the connectivity robustness also have an impact on the performance of traffic condition estimation models, a direct relationship between connectivity robustness and traffic condition estimation performance was established. Simulation results show that the CONROB model can be used as a tool to predict the accuracy of the estimated traffic conditions (e.g. travel times), as well as the reliability of such estimates, given specific system characteristics. The optimal deployment of road-side units (RSUs) is another important factor that affects the communication stability and the traffic conditions estimates and reliability. Thus, an optimization approach was developed to identify the optimal RSUs locations with the objective function of maximizing the connectivity robustness. Simulation results for the developed approach show that CONROB model can help identify the optimal RSUs locations. This shows the importance of CONROB model as a planning tool for CV environments. For the individual user performance characteristics, a preliminary driving simulator test bed for CV technology was developed and tested on thirty licensed drivers. Forward collision warning messages were delivered to drivers when predefined time-to-collision values take place. The findings show improved reaction times of drivers when receiving the warning messages which lend credence to the safety benefits of the CV technology

Data Support of Advanced Traveler Information System Considering Connected Vehicle Technology

Traveler information systems play a significant role in most travelers’ daily trips. These systems assist travelers in choosing the best routes to reach their destinations and possibly select suitable departure times and modes for their trips. Connected Vehicle (CV) technologies are now in the pilot program stage. Vehicle-to-Infrastructure (V2I) communications will be an important source of data for traffic agencies. If this data is processed properly, then agencies will be able to better determine traffic conditions, allowing them to take proper countermeasures to remedy transportation system problems under different conditions. This research focuses on developing methods to assess the potential of utilizing CV data to support the traveler information system data collection process. The results from the assessment can be used to establish a timeline indicating when an agency can stop investing, at least partially, in traditional technologies, and instead rely on CV technologies for traveler information system support. This research utilizes real-world vehicle trajectory data collected under the Next Generation Simulation (NGSIM) program and simulation modeling to emulate the use of connected vehicle data to support the traveler information system. NGSIM datasets collected from an arterial segment and a freeway segment are used in this research. Microscopic simulation modeling is also used to generate required trajectory data, allowing further analysis, which is not possible using NGSIM data. The first step is to predict the market penetration of connected vehicles in future years. This estimated market penetration is then used for the evaluation of the effectiveness of CV-based data for travel time and volume estimation, which are two important inputs for the traveler information system. The travel times are estimated at different market penetrations of CV. The quality of the estimation is assessed by investigating the accuracy and reliability with different CV deployment scenarios. The quality of volume estimates is also assessed using the same data with different future scenarios of CV deployment and partial or no detector data. Such assessment supports the identification of a timeline indicating when CV data can be used to support the traveler information system

Coordinated Transit Response Planning and Operations Support Tools for Mitigating Impacts of All-Hazard Emergency Events

This report summarizes current computer simulation capabilities and the availability of near-real-time data sources allowing for a novel approach of analyzing and determining optimized responses during disruptions of complex multi-agency transit system. The authors integrated a number of technologies and data sources to detect disruptive transit system performance issues, analyze the impact on overall system-wide performance, and statistically apply the likely traveler choices and responses. The analysis of unaffected transit resources and the provision of temporary resources are then analyzed and optimized to minimize overall impact of the initiating event

2nd Symposium on Management of Future motorway and urban Traffic Systems (MFTS 2018): Booklet of abstracts: Ispra, 11-12 June 2018

The Symposium focuses on future traffic management systems, covering the subjects of traffic control, estimation, and modelling of motorway and urban networks, with particular emphasis on the presence of advanced vehicle communication and automation technologies. As connectivity and automation are being progressively introduced in our transport and mobility systems, there is indeed a growing need to understand the implications and opportunities for an enhanced traffic management as well as to identify innovative ways and tools to optimise traffic efficiency. In particular the debate on centralised versus decentralised traffic management in the presence of connected and automated vehicles has started attracting the attention of the research community. In this context, the Symposium provides a remarkable opportunity to share novel ideas and discuss future research directions.JRC.C.4-Sustainable Transpor