This poster session contains presentations on various managed lane and congestion pricing projects and research that focus on topics related to automated and connected vehicles, active traffic management, geometric design, urban mobility, and freeway operations.
Assessing Impacts of Predictive Transportation Management Over Responsive Action Plans Using Simulation Based Approach
Boon Teck Ong, Booz Allen Hamilton, Inc.Show Abstract
Raj Kamalanathsharma, Booz Allen Hamilton
Balaji Yelchuru, Audi of America
Active traffic management and active demand management are used to mediate congestion to improve traffic operations through various strategies. Most standard practice by agencies are limited to the use of static time-of-day plans or reactive-plan selection due to their proven benefits and relatively lower complexity. This research assesses the use of proactive management compared to reactive management when activating the active traffic management and active demand management response plans by comparing their operational benefits. A comprehensive integration of mesoscopic simulation as a predictive tool with microscopic simulation as an analysis tool was designed to evaluate the operational benefits of these two management strategies. The Pasadena simulation testbed network made available as opensource on FHWA Research Data Exchange portal was used for the assessment of this research. The active traffic management strategies assessed are Adaptive Ramp Metering (ARM), Dynamic Signal Control (DSC), Dynamic Shoulder Lane (DShL), and Dynamic Junction Control (DJC). The active demand management strategy assessed is Dynamic Route Guidance. The results demonstrated higher operational benefits when response plans are implemented through proactive management compared to responsive. Using network travel time as a performance measure, the results are summarized as follows: ARM shows 2.45% reduction with predictive while 0.58% with reactive; DSC shows 0.77% reduction with predictive while 0.47% with reactive; DShL+DJC show 7.77% reduction with predictive while 2.01% with reactive; and DRG shows 2.10% reduction with predictive while 0.29% with reactive. Using traffic prediction methodology as a response plans are implemented prior to when traffic congestion becomes too heavy.
Dedicating Lanes for Priority or Exclusive Use by Connected and Automated Vehicles
Boon Teck Ong, Booz Allen Hamilton, Inc.Show Abstract
Raj Kamalanathsharma, Booz Allen Hamilton
Balaji Yelchuru, Audi of America
Connected and automated vehicles (CAVs) are quickly expanding in the automobile and transportation industry and are expected to become a major share of the market in the next decade. Agencies are preparing themselves for this disruptive change, which can bring in safety, mobility, and operational benefits. A simulation-based analysis was conducted on CAV applications, namely Cooperative Adaptive Cruise Control (CACC) and Dynamic Speed Harmonization (DSH). The assessment was performed under isolated and combination application deployment on a freeway facility during PM peak hour for 4 hours analysis period. The testbed facility used for this simulation effort is the I-66 freeway assuming the operating rule where the left most lane is dedicated for CAV use only. The simulation results show that at 25% CAV market penetration, DSH and CACC combination improves vehicle throughput by an average of approximately 2% which is similar to CACC application in isolation. Safety performance is improved under the CACC and DSH combination due to the reduction in rapid change in speed profile across the roadway facility. A minor improvement in environmental impact is observed due to the reduction in fuel consumption with the application of CACC and DSH in combination compared to when the CAV applications were implemented in isolation. Dedicating lane to CAV exclusive use shows a degradation in operational performance measured in vehicle throughput at 10% market penetration but improves when market penetration reaches 25%. Overall the deployment of CACC and DSH CAV application yields synergic effects.
Evaluating the Effectiveness of Bundled Connected Automated Vehicle Applications Applied to Freeway Managed Lanes
Yi Guo, University of CincinnatiShow Abstract
Jiaqi Ma, University of Cincinnati
Edward E. Leslie, Leidos
Zhitong Huang, Leidos, Inc.
The purpose of this study is to define a promising operational concept involving connected automated vehicle (CAV) operation on freeway managed lanes. Despite the low projected market penetration of CAVs during the next decade, the use of managed lane facilities has the potential to support the realization of increased mobility benefits by their very nature. The proposed CAV operation involves platoons of equipped vehicles governed by bundled CAV applications, including cooperative adaptive cruise control (CACC), cooperative merge, and speed harmonization. This study proposes an integrated algorithm for the bundled CAV application. Through microscopic simulation, the study particularly examines the effectiveness of CACC, CACC plus cooperative merge, and the addition of speed harmonization under different penetration rates. Simulation results shows the effectiveness of the bundled application to enhance system throughput and reduce delay even with low CAV penetration rates. The speed harmonization only shows significant effectiveness with high CAV penetration, but the potential safety benefits it brings to the system, though not evaluated in the study, can be quite significant. The conclusions provide operational insights and guidance for traffic management centers to implement CAV-based traffic control in the future.
Concept of Operations: Applying Bundled Speed Harmonization, Cooperative Adaptive Cruise Control, and Cooperative Merging Applications to Managed Lane Facilities
Jiaqi Ma, University of CincinnatiShow Abstract
Sonika Sethi, Leidos
Edward E. Leslie, Leidos
Tao Li, University of Cincinnati
The purpose of this study is to define the top-priority operational concept involving connected automated vehicle operation on managed lanes (CAV ML). The policies and scenarios associated with this concept should be chosen and designed to facilitate rapid and successful deployment of a solution that has yet to be deployed anywhere. The proposed CAV operation involves platoons of equipped vehicles governed by an integrated set of cooperative adaptive cruise control (CACC), cooperative merging, and speed harmonization algorithms. The concept accounts for CACC vehicle behaviors in the vicinity (both upstream and downstream) of managed lane entry ramps. The concept further addresses platooning and cooperative merging on the managed lane and considers the managed lane parameters that affect CAV operation including design characteristics, physical characteristics, operational parameters, and technology requirements. The study also examines the organizational and institutional frameworks and stakeholder roles and engagement required to implement the proposed concept on a typical managed lane facility. Although managed lanes have several types of operations, supporting infrastructures, and organizational structures; most implementations have several common elements. The study provides a roadmap to leverage these common elements to support the CAV operational scenarios. It also presents a framework to examine which managed lane elements are most suitable for the proposed concept. Finally, the study identifies the goals and metrics of CAV operation that may align with and help further the goals of managed lane operations.
The Effectiveness of Managed Lane Strategies for the Near-Term Deployment of Cooperative Adaptive Cruise Control
Zijia Zhong, University of DelawareShow Abstract
Joyoung Lee, New Jersey Institute of Technology
Traffic simulation is a cost-effective way to test the deployment of Cooperative Adaptive Cruise (CACC) vehicles in large-scale transportation network under various traffic conditions. This paper examines the impacts of four managed lane strategies for the near-term deployment of CACC under mixed traffic conditions with a previously developed microscopic simulation testbed. Network-wide performed measures for CACC are investigated from the perspectives of mobility, safety, equity, environment. In addition, vehicle platooning is evaluated with the percentage of platooned CACC vehicles, average position within platoon, and vehicle hour platooned which is a new measure proposed. Moreover, a managed lane score matrix is developed to incorporate different categories of performance measures, aiming to provide a more comprehensive picture for stakeholders. The results show that mixing CACC traffic across all travel lanes is an acceptable option when the market penetration rate (MPR) is lower than 30% for roadways without any existing managed lanes. Providing CACC with priority access to an existing High-occupancy vehicle lane, if available, is also a good strategy for improving traffic performance when the MPR is lower than 40%. When the MPR reaches higher than 40%, a dedicated lane for CACC is recommended for providing greater opportunity to form CACC platoons and creating a homogeneous traffic flow of CACC vehicles.
Equity and Emissions Considerations in Autonomous Vehicle Dedicated Lane Deployment Scheme
Young Joun Ha, Purdue UniversityShow Abstract
Mohammad Miralinaghi, Purdue University
Samuel Labi, Purdue University
The goal of this research is to control the amount of greenhouse gas (GHG) emissions by addressing the equity concerns due to dedicated lanes to autonomous vehicles (AVs). Since AVs can more efficiently operate in urban areas compared to conventional vehicles, promoting AVs is an essential tool in achieving emission reduction goals. A robust way to achieve AV adoption is through providing AV-only lanes, which will provide a significantly reduced travel time, incentivizing AV adoption. As such, this research will focus on developing an AV-only lane deployment scheme. However, an aggressive AV-only lane deployment can significantly increase the travel time of conventional vehicles (CVs) due to a reduction of available lanes for CVs. There are equity implications involved as conventional vehicles are more likely to be used by low-income travelers due to more affordable prices compared to those of AVs. This research addresses this equity concerns to make the AV-only lane sustainable in practice.
Innovate 680: A Multi-Strategy and High-Tech Solution for Optimized Mobility
Tim Haile, Contra Costa Transportation AuthorityShow Abstract
The Innovate 680 program of projects combines past improvements already operational with improvements currently underway and future improvements to the highway into a new Integrated Corridor Management (ICM) system. These innovative improvements will turn the tide of escalating congestion and delays by using all the best emerging technologies that collectively lead to smart mobility. The ICM system will establish and maintain non-congested highway operations, respond to events that tend to introduce congestion and more fully utilize all available public transportation assets including trains, buses, and parking spaces. All available and proven ITS technologies will be deployed, integrated into ICM System, and leveraged to measure, adjust, and maximize mobility. Rather than focus on only the congested freeway, the program will take a holistic approach to evaluating the entire system such as local roads, major arterials, express lanes and freeway systems while leveraging transit to improve mobility and provide a seamless door to door journey. With this high-tech approach, the project can improve mobility and reduce congestion, improve road safety, increase transit ridership, bolster access to transit, stabilize system reliability and promote environmental sustainability.
Innovate 680 is a seven-strategy integrated approach that is currently in its implementation process to address the both the demand side and the supply side of mobility along the I-680 in Northern California.
Assessing HOV Lane Utilization and Occupancy Rates in Tennessee
Deo Chimba, Tennessee State UniversityShow Abstract
Janey Camp, Vanderbilt University
Kevin Soloka, Tennessee State University
Jason Oldham, Tennessee Department of Transportation
Brad Freeze, Tennessee Department of Transportation
This study evaluated the performance of existing HOV lanes in Tennessee as travel-time incentives for promoting carpooling and reducing congestion. While the overall person-moving capacity of the HOV lanes may be slightly higher than the general-purpose lanes, the travel–time incentives for legitimate HOV lanes users have been severely diminished by violators in Tennessee. The study conducted literature review on HOV lane occupancy detection technologies that could assist in managing HOV corridors while assisting in evaluation of performance strategies to address high violation rates. Furthermore, the study evaluated HOV lane utilization rates and HOV lane occupancy violation rates in the state. Estimating utilization rate as the percentage of vehicles that use the HOV lane compared to all other General Purpose (GP) lanes, the paper found that the average HOV lanes utilization in Tennessee is 23% and the HOV lane violation rate is about 84%. The HOV lane occupancy violation rates was evaluated by taking the percentage of Single Occupancy vehicles (SOVs) to the total vehicles using HOV lane during study AM and PM peak hours. It was found that only 15% to 20% of vehicles using HOV lanes in Tennessee are those with 2+ occupancy as required by law, the remaining 80% to 85% are single occupancy vehicles (SOVs). Findings are expected to support at large the operational goals of transportation agencies on HOV systems improvement strategies.
Analysis of High-Occupancy Vehicle (HOV) Lanes During Active and Inactive Time: An Empirical Study of HOV Lanes in Tennessee
Nima Hoseinzadeh, University of Tennessee, KnoxvilleShow Abstract
Yuandong Liu, University of Tennessee, Knoxville
Lee Han, University of Tennessee, Knoxville
High-Occupancy Vehicle (HOV) facilities aim to move more people and, hence, improve the overall performance of the highway segment by reducing travel time, increasing average operational speed, and reducing traffic congestion. Although many studies have been conducted on HOV lane performance, the HOV facility performance during the inactive time, typically off-peak period, has received limited attention. During HOV inactive time, HOV lanes are typically reverted to and treated as general purpose (GP) lanes. A key aspect of the study presented herein focuses on the performance of HOV under such conditions, namely, the observed driver preferences and use patterns of HOV lanes under congested/ uncongested condition and during HOV active/inactive time. Data of Part-time HOV lanes from radar detection system (RDS) near Nashville, Tennessee were collected and evaluated. The findings of the study include (1) during congested condition in HOV active time, HOV lanes has lower speed and higher flow than adjacent GP lanes, (2) HOV lanes tend to be underutilized in uncongested area during HOV active, and (3) drivers are reluctant to use HOV facilities during inactive time and weekends. This mean HOV lanes during HOV inactive time are underutilized and do not really work as GP lanes. They can almost be considered as “full-time” HOVs. Also, drivers are not willing to use HOV lanes unless they confront congestion. This study tries to address an HOV lane malfunction during the inactive time and uncongested time. For future studies, the authors will try to answer many questions about why this happens.
A Driving Simulator Study to Investigate Drivers' Lane Change Behavior on the Weaving Section of a Freeway with Managed Lane
Jinghui Yuan, University of Central FloridaShow Abstract
Mohamed Abdel-Aty, University of Central Florida
Qing Cai, University of Central Florida
Jaeyoung Lee, University of Central Florida
Managed lane (ML) system has been widely implemented on freeways to mitigate congestion and improve efficiency. ML was usually designed as concurrent with general purpose lanes (GPLs), and separated by a barrier or painted stripe with several at-grade ingresses and egresses. However, this kind of design may result in weaving segments between ingress (egress) and nearest on-ramp (off-ramp). For example, a vehicle from an on-ramp must cross multiple GPLs to get access to the ML. This study aims to investigate the safety effects of weaving length, traffic condition, and driver characteristics on drivers’ mandatory lane change behavior based on a driving simulator study. Mixed factorial design with two within-subjects factors (traffic volume: off-peak and peak; speed harmonization (SH): SH and Non-SH) and one between-subjects factor (weaving length per lane change (L_LC): 600 feet, 1,000 feet, and 1,400 feet) were employed in this study. Fifty-four licensed drivers were recruited to conduct this driving simulator experiment. Based on the experimental data, three lane change decision metrics, three lane change execution metrics, and two surrogate-safety metrics were analyzed. Results indicated that for the ingress of MLs (entrance weaving segment), 1,000 feet L_LC would be recommended if the space is limited, otherwise 1,400 feet L_LC is more preferable. For the egress of MLs (exit weaving segment), however, only 1,000 feet L_LC was recommended since the 1,400 feet L_LC was found to be significantly more dangerous than the 600 and 1,000 feet L_LC.
Analysis of the Effects of an HOV Lane on a German Freeway: A Simulation Study with PTV Vissim
Claude M. Weyland, Karlsruhe Institute of Technology (KIT)Show Abstract
H. Sebastian Buck, Karlsruhe Institute of Technology (KIT)
Peter Vortisch, Karlsruhe Institute of Technology (KIT)
Verena Zeidler, Karlsruhe Institute of Technology
The objective of our research is to assess the effects of a high occupancy vehicle (HOV) lane on a German federal freeway. The research findings provide guidance for practitioners for the development of a microscopic traffic flow model containing temporary hard shoulder running and an HOV lane in PTV Vissim. We developed a microscopic traffic flow model of a section of a German freeway. The driving behavior was calibrated with measured traffic data of the existing dynamic line control system. We used this model to simulate 16 scenarios of an HOV lane (four HOV lane designs combined with four vehicle occupancies). The results showed the desired effects of an HOV lane can only be achieved to a small extent. The reduction of general purpose lane capacity is too high when introducing an HOV lane. Furthermore, the introduction of an HOV lane results in additional lane changes in the upstream area from the HOV lane in the simulation. The reduced capacity in combination with increased lane changes leads to congestion, both for HOVs and SOVs. Only on the section of the HOV lane itself, HOVs are faster than SOVs. Downstream the traffic situation remains the same as in the baseline scenario. Therefore, the potential for travel time savings for HOVs compared to SOVs is low. One of four HOV lane designs offers 4 minutes travel time savings for HOVs over SOVs. It is questionable whether a minor time gain is enough to change people's mobility behavior towards carpooling.
Development and Application of a Queue Accumulator Model In Toll Road and Managed Lane Modeling
Yandin Lu, CDM SmithShow Abstract
Phani Jammalamadaka, CDM Smith
Michael Penic, WSP-USA
Queue Accumulator (QA) is a model that estimates travel delay by studying the interaction between travel demand and roadway capacity supply from an operational perspective. It takes the roadway configurations and loaded volumes from the travel demand model as inputs and produces practical capacity, adjusted demand, and travel delay information as a feedback to travel demand model. The QA is built by using Python, a free and open source programming language, and has been seamlessly integrated with a toll diversion traffic assignment model. The QA can perform analysis on multiple toll road and managed lane corridors at a time.
Controlling Bottleneck Queue with a Tradable Credit Scheme Under Commuter Heterogeneity and Market Loss Aversion Behavior
Mohammad Miralinaghi, Purdue UniversityShow Abstract
Srinivas Peeta, Purdue University
Xiaozheng He, Rensselaer Polytechnic Institute (RPI)
Satish Ukkusuri, Purdue University
This study analyzes the effect of a tradable credit scheme (TCS) on morning bottleneck congestion by considering commuters’ value-of-time and schedule delay heterogeneities, and loss aversion behavior in purchasing credits. The TCS consists of group-specific credit allocation and time-varying credit charging schemes. Commuters trade credits in the market based on their initial credit endowments, travel needs, and loss aversion behavior towards purchasing credits in the market. Commuters valuate the charged credits of departure time choice as monetary gains or losses relative to their initial endowments. The existence and uniqueness of equilibrium departure rates, credit price (CP) and travel disutility are investigated under this TCS. The system optimal (SO) design of the TCS is formulated by applying linear programming duality to derive the TCS parameters that lead to the SO solution in terms of the sum of the schedule delay and travel time costs. It illustrates that CP and total value of traded credits approach zero as commuters’ loss aversion increases. Further, the initial credit allocation method can impact the CP and commuters’ departure rate. The study findings suggest that if commuters’ loss sensitivity is not considered, the SO TCS design can lead to a less effective scheme to minimize the total system travel cost.
Ridesourcing Dynamic Pricing in Non-Equilibrium Networks
Mehdi Nourinejad, University of TorontoShow Abstract
Mohsen Ramezani, University of Sydney
Ride-sourcing services are a prominent mobility mode because of their cost-effectiveness and convenience. They provide a platform that acts as a two-sided market by matching passengers and vacant taxis (or other types of drivers). The conventional ride-sourcing models are based on the equilibrium approach where the demand is cleared (i.e., market clearance) in each time step, and the vacant taxis decide whether to remain or exit the market. This approach is not suitable for operational decision-making where there are noticeable variations in the state of the system, denying the market enough time to balance back into equilibrium. In this paper, we propose a controller based on the model predictive control approach to maximize the service provider's profit by dynamically controlling the fare offered to passengers and the wage offered to taxis. We asses three pricing strategies where the fare and wage are (i) dynamic and unconstrained, (ii) dynamic and constrained so that the instantaneous profit is positive, and (iii) static and fixed throughout the planning horizon. The results demonstrate that the dynamic and unconstrained strategy has the highest overall profit although it set the wage higher than the fare when the passenger demand peaks.
Reliability Constrained Cordon Pricing in Traffic Networks Under Stochastic Demand
Can Zhang, University of AlbertaShow Abstract
Chen Qiu, University of Alberta
Tony Qiu, University of Alberta
A general target of cordon pricing is used to control the traffic demand into a cordon area through charging an entry fee. However, in stochastic networks, it is nearly impossible to absolutely control the traffic demand into the cordon area within a threshold through cordon pricing. This paper aims to find a reliability-based cordon pricing scheme, which would control the cordon-in traffic demand to sit below a threshold with a predetermined probability. Two implementation scenarios are considered, i.e., with and without complete information about the travel cost. For the scenario without complete information, travelers are assumed to choose paths with the minimum expected travel time. A reliability constrained cordon pricing (RCCP) model is established to determine the minimal toll which controls the number of cordon-in vehicles to be less than a threshold with a predetermined probability. For the scenario with complete information, travelers are assumed to choose paths with minimum travel time from day to day. Moreover, the network attaches Wardrop’s User Equilibrium within each day. In the well-done days, the daily number of vehicles into a certain area is controlled within a specified threshold. A frequency constrained cordon pricing (FCCP) model is established to find the minimal toll which controls the frequency of well-done days to be a predetermined value. This paper further analyzes the differences between the RCCP model and the FCCP model. Solution algorithms and numerical examples are conducted to demonstrate both the models.
Spatio-Temporal Analysis of Congestion at Proposed Congestion Pricing Zone in New York City
Anil Yazici, SUNY College, Stony BrookShow Abstract
Amirmasoud Almotahari, SUNY College, Stony Brook
Lucas Fressynet, Transportation Infrastructure Office French Ministry of Transport
Ludovic Leclercq, IFSTTAR
Ayberk Kocatepe, Modeler, Travel Modeling and Analytics Connetics Transportation Group
Eren Ozguven, Florida A&M University
In this paper, a spatio-temporal analysis of congestion in New York City (NYC) is performed and the implications on the proposed congestion pricing plan for the city are discussed. For this purpose, taxi GPS trip dataset provided by NYC Taxi and Limousine Commission (TLC) is utilized. Since the dataset includes only the trip origins and destinations, the trip routes are estimated. The shortest paths inside NYC’s proposed congestion pricing area are calculated using Djikstra’s algorithm, and taxi trip paths are estimated and assign onto network links based on calculated shortest paths and heuristics, e.g. taxi driver’s preference to make fewer turns. The travel times are calculated through least squares solution of a set of linear equations and normalized by link distances to obtain the travel rates (minutes per mile). Hourly travel rates are utilized in Kernel Density Estimation to obtain spatio-temporal congestion. The results show that there are higher levels of congestion at vicinity of the cordon boundaries and connections to New Jersey and other NYC boroughs. It is discussed that congestion on east-west alignment is more critical than it is on north-south alignment. The findings support the latest congestion pricing plan (MoveNY) in two aspects. First, a dynamic congestion pricing system can be more efficient than the current fixed tolling system. Second, imposing toll on Brooklyn and Williamsburg bridges can relieve localized traffic hotspots by making the traffic more homogenous within the whole Manhattan and would be beneficial in terms of equity and financial resources for public transportation investments.
Traffic and Revenue Forecast Model for I-95 Phases 1, 2, and 3 Express Lanes in South Florida
Ozge Cavusoglu, CDM Smith
Phani Jammalamadaka, CDM Smith
Behavioral and Operational Considerations in the Implementation of Automated HOV Enforcement in Tennessee HOV Corridors
Mark McDonald, Lipscomb University
Yu-Jen Chen, Tennessee Department of Transportation
Better Service for Sustainable Mobility: TEXpress Managed Lanes Benefits and Customer Experience
Ning Zhang, NTE Mobility Partners
Thu Hoang, LBJ Infrastructure Group