Set Of Lanes Research Articles

Collaborative control framework at isolated signalized intersections under the mixed connected automated vehicles environment

AbstractThis study proposes a collaborative control framework under the mixed traffic environment of connected and automated vehicles and connected human‐driven vehicles, which can simultaneously optimize the signal timing, lane settings, and vehicle trajectories at isolated intersections. Initially, considering the dynamics of traffic demand and incompatible signals, we analyze the vehicle delay of each lane. Based on the delay analysis, the spatiotemporal resource collaborative optimization model of lane setting and signal timing is established to minimize the average delay. Subsequently, in the buffer zone, a graph‐theoretic‐based sorting and platooning model provides a clear and concise representation of the transformation process from the initial state to the target state of vehicles, enabling the platoon formation. Additionally, trajectory optimization is integrated into the collaborative control framework by the optimal control model and car‐following model in the passing zone. Simulation experiments and sensitivity analyses demonstrate the effectiveness of the proposed framework in reducing average vehicle delay, improving fuel consumption, and coping with changing traffic demand at intersections.

Managing Limited Access Highways for High Performance: Costs, Benefits, and Revenues

Managed lanes are a set of lanes where highway operations strategies are actively applied in response to changing conditions. High-Occupancy/Toll (HOT) and Express Toll lanes are examples of managed lanes. The transportation operations concept discussed in this article involves conversion of existing freeways (all lanes) into premium-service free-flowing highways that provide fast, frequent, and inexpensive express bus service and charge all private vehicles a variable toll—except for authorized buses and certified ridesharing vehicles. The toll would vary by level of demand and would be set high enough to guarantee that excessive demand will not cause a breakdown of traffic flow. This article discusses the advantages of this concept. It introduces a new sketch-planning tool that provides estimates of costs, benefits, and revenues from applying the concept on a highway network in a prototypical large metropolitan area. The estimates suggest that implementing the concept can provide significant net social benefits. It may also generate sufficient new toll revenue to pay for all costs for implementation and operation, including new express bus and park-and-ride services that would complement the pricing scheme.

Benefit analysis and evaluation of bus lane setting

By combing the static theoretical model with the dynamic simulation model, we develop a benefit index evaluation method for bus lane setting. By using mathematical theoretical model and simulation software VisSim, we obtain the changes of indexes under the conditions of whether or not to set the bus lane to investigate the comprehensive evaluation method of the benefits of bus lane setting and to improve the accuracy of the evaluation results. The evaluation results show that the bus lane has the best benefit when the road saturation is 0.76. It is confirmed that while the results of mathematical theoretical model can provide references for the simulation model during parameter setting, the simulation results can make a comparative analysis with the mathematical results as well to verify the validity of theoretical model and to ensure the accuracy of the final benefit evaluation result. This research explores the critical conditions such as optimal saturation, and provides a theoretical reference of bus lane setting. This method improves the reliability and robustness of benefit evaluation of bus lane setting and provides a reference for improving the accuracy of simulation modeling.

Research on Decision Evaluation Model of HOV Lane Setting

In order to achieve the purpose of improving the travel efficiency of commuters in the periphery of the city, expanding the beneficiary groups of urban rail transit, and alleviating urban road traffic congestion, when planning and setting up HOV in the periphery of the city, it is necessary to analyze the feasibility of HOV lane setting from both the demand conditions and the setting conditions. This paper combines machine learning to construct a decision-making evaluation model for HOV lane setting and studies the optimal layout model and algorithm of HOV lanes in service rail transit commuter chain. The setting, planning, and layout of HOV lanes are a two-way interactive process of traveler's path selection and designer's road planning. Finally, after the model is constructed, the performance of the system model is verified. The results show that the system studied in this paper can be used for traffic data and lane planning analysis. Therefore, in the process of urban operation, the HOV model constructed in this paper is mainly used to alleviate urban traffic and improve urban operation efficiency.

Influence of Lane Policies on Freeway Traffic Mixed with Manual and Connected and Autonomous Vehicles

Connected and autonomous vehicles (CAVs) have become the highlights of traffic. Researchers in this field have proposed various traffic management measures to enhance the capacity and efficiency of traffic with CAVs, especially mixed traffic of CAVs and manual vehicles (MVs). Exclusive lane setting is included. However, exclusive lane policy-related researches for mixed traffic of CAVs and MVs were very limited, and the influence of number and location of exclusive lanes on the mixed traffic was unclear. To fill this gap, this paper aims to study the influence of different exclusive lane policies on mixed traffic and provide recommended lane policies under various traffic volumes and CAV penetration rates. Freeways with two lanes and three lanes in a single direction were taken into consideration, and sixteen lane policies were proposed. Then different lane policies were simulated with a new proposed cellular automata (CA) model, and properties including flux, average speed, and CAVs degradation were analyzed to evaluate the traffic efficiency of each lane policy. The results show that CAV exclusive lanes can improve the capacity, while MV exclusive lanes seem helpless for capacity improvement. Seven lane policies, including GC, GM, and CM for two-lane freeways and GCG, CGC, and CCM for three-lane freeways, outperform the others in terms of average speed. In addition, exclusive lanes can reduce the probability that CAVs degenerate to AVs. Our findings may help to optimize freeways’ lane policies and improve the efficiency of heterogeneous traffic mixed with CAVs and MVs.

A Cooperative Algorithm for Lane Sorting of Autonomous Vehicles

In this paper, we propose a generalized algorithm that converts traffic composed of vehicles located randomly in a set of lanes into sorted traffic in which vehicles are moved into the lane corresponding to their destination group. Focus is placed on the cooperative behavior of vehicles. The proposed algorithm architecture divides the entire scenario into various independent sections (called frames) that can be processed in parallel at the same time. Processing each frame involves solving an optimization procedure of a nonlinear programming problem reducible to a linear programming problem. The performance of the proposed algorithm is tested using the Simulation of Urban MObility (SUMO) simulator. Results are obtained and presented for average sorting distance required for sorting all vehicles in the scenario for different traffic settings.

Ara: A 1-GHz+ Scalable and Energy-Efficient RISC-V Vector Processor With Multiprecision Floating-Point Support in 22-nm FD-SOI

In this article, we present Ara, a 64-bit vector processor based on the version 0.5 draft of RISC-V's vector extension, implemented in GlobalFoundries 22FDX fully depleted silicon-on-insulator (FD-SOI) technology. Ara's microarchitecture is scalable, as it is composed of a set of identical lanes, each containing part of the processor's vector register file and functional units. It achieves up to 97% floating-point unit (FPU) utilization when running a 256 × 256 double-precision matrix multiplication on 16 lanes. Ara runs at more than 1 GHz in the typical corner (TT/0.80 V/25 °C), achieving a performance up to 33 DP-GFLOPS. In terms of energy efficiency, Ara achieves up to 41 DP-GFLOPS W <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-1</sup> under the same conditions, which is slightly superior to similar vector processors found in the literature. An analysis on several vectorizable linear algebra computation kernels for a range of different matrix and vector sizes gives insight into performance limitations and bottlenecks for vector processors and outlines directions to maintain high energy efficiency even for small matrix sizes where the vector architecture achieves suboptimal utilization of the available FPUs.

A longitudinal study of bike infrastructure impact on bikesharing system performance in New York City

The sustainability of bikesharing systems depends on the bicycle network connectivity and accessibility. However, studies of bike lane infrastructure investment impacts on bikesharing ridership have been limited to station-level ridership to support bikeshare operators’ resource allocation decisions. City planning agencies also need to forecast and analyze bikeshare demand in order to make investment decisions of bike facilities over time. To measure the marginal effect of building bike lanes on bikeshare demand at a network-wide level over time, an autoregressive conditional heteroscedasticity (ARCH) model with autoregressive (AR) disturbance is proposed to capture system-wide bike ridership. The model is applied to investigate the relationship between bikeshare average daily trip counts and the total length of bike lanes in New York City (NYC) regardless of specific locations. Our results show that the installation of one additional mile of bike lanes in NYC led to an average increase of 102 bikesharing daily trips. Spatial heterogeneity is addressed through two market segments by borough (Manhattan vs. Non-Manhattan), which indicates that the improvement of bike lanes had a significant impact on bikesharing ridership in Manhattan, generating 285 more trips with one mile of bike lane built in Manhattan, but was not as effective outside of Manhattan. In addition, model results show that there were 135 and 13 more trips generated per day when one more bikesharing sharing station was added in Manhattan and Non-Manhattan, respectively. The marginal effect could vary due to the specific implemented location of a bike lane. We demonstrate that this model, as opposed to the previous studies in the literature developed at the station-level, can provide new insights into system-level causality and temporal lag characteristics. When considering whether a city agency should install a set of bike lanes immediately or to stage them over multiple weeks, the “discount rate” for ridership benefits is estimated via a proposed model for different types of investment. The results of investment scenario analysis show that there is a higher effective “discount rate” for ridership benefits from front-loading all of the investment.

Research on Microscopic Traffic Simulation Model in VISSIM

VISSIM is a microscopic, time-interval and driving behavior-based simulation modeling tool for traffic modeling of urban traffic and public transportation operations, It can be used to analyze various traffic conditions, such as lane setting, traffic composition, traffic signals, bus stops, urban traffic and public transport operations, is an effective tool for evaluating traffic engineering design and urban planning solutions. This paper mainly studies the system architecture and simulation basic principle of VISSIM traffic simulation environment software, and introduces its core model-vehicle follow-up model and vehicle lane change algorithm in detail, and designs a simulation example plot to verify the traffic simulation model.

Heuristic methods for the periodic Shipper Lane Selection Problem in transportation auctions

In the Shipper Lane Selection Problem (SLSP) a set of lanes should be classified either to be serviced by the shipper’s fleet or through auction. However, it is common in real-life problems that the same lane should be served multiple times during the planning horizon. In this study, the periodicity nature of the problem is incorporated into the SLSP. Thus, a novel variant of the problem, namely the Periodic SLSP (P-SLSP) is introduced. The aim is to achieve savings on the shipper transportation costs over the extended horizon. The problem is modeled as an integer programming formulation and solved first with a general purpose software. Subsequently, three different heuristic methods have been developed to overcome the limitation of the exact full-space method. The validity of the model as well as the efficiency of the heuristics have been tested by using a properly modified set of Solomon’s benchmark problems. Intensive computational analysis indicates the appropriateness of the proposed heuristics and their relevance for solving large-scale P-SLSPs.

Development and comparison of choice models and tolling schemes for high-occupancy/toll (HOT) facilities

A high-occupancy/toll (HOT) lane is an increasingly popular form of traffic management strategy which reserves a set of freeway lanes for HOVs and transit users, while allowing low-occupancy vehicles (LOVs) to enter for a fee. In turn, HOT lanes maintain a minimal level of service by regulating the volume of entering LOVs. The focus of this paper is how to model the choice process of individual drivers, which dictates the volume of LOVs that choose to pay and take the HOT lane. Such models and the insights they provide can be very helpful for the toll setting process. Two simple formulations (an all-or-nothing assignment and an additive logit model) are compared with a proposed formulation based on the population value of time (VOT) distribution. Both static and dynamic toll setting algorithms are studied based on the proposed lane choice model, and their performance is compared under deterministic traffic behavior.

Automatic Lane Segmentation in TLC Images Using the Continuous Wavelet Transform

This paper describes a new methodology for lane detection in Thin-Layer Chromatography images. An approach based on the continuous wavelet transform is used to enhance the relevant lane information contained in the intensity profile obtained from image data projection. Lane detection proceeds in three phases: the first obtains a set of candidate lanes, which are validated or removed in the second phase; in the third phase, lane limits are calculated, and subtle lanes are recovered. The superior performance of the new solution was confirmed by a comparison with three other methodologies previously described in the literature.

The lane covering problem with time windows

The Lane Covering Problem with Time Windows arises in the context of collaborative logistics. Given a set of lanes, it aims at finding a set of tours covering all lanes with the objective of minimizing the total travel cost. The purpose of this paper is to formulate a model for such a problem and to propose a heuristic approach based on Lagrangian relaxation for its solution. The behavior of this procedure is tested on a set of random instances.

Lane-Based Network for Flow Analysis and Inventory Management of Transportation Networks

The widely accepted link–node centerline network model inhibits lane-based traffic analysis and inventory management, specifically the ability to represent the availability of lanes, individual lane properties, connectivity among parallel lanes and at turns, and lane movement restrictions. A lane-based network overcomes the limitations by maintaining lanes as independent topological objects and thus supports data management, decision making, and network analysis at the lane level. The data model for a lane-based network uses a directed graph approach in which a set of unidirectional lanes and nodes is used to model traffic flow connectivity. The model manages the continuous lateral connectivity between parallel lanes by specifying the relative lateral position of the lanes on their parent roadways. This approach provides an efficient way to maintain lane topology and eliminates the requirement of turntables. This paper presents the model along with guidelines for lane-based inventory management and strategies for discretizing continuous lateral connectivity between parallel lanes to enable the use of existing routing algorithms (e.g., Dijkstra's). Finally, the paper presents a practical implementation built on the linear location referencing system of a state department of transportation.

Lane-Based Network for Flow Analysis and Inventory Management of Transportation Networks

The widely accepted link-node centerline network model inhibits lanebased traffic analysis and inventory management, specifically the ability to represent the availability of lanes, individual lane properties, connectivity among parallel lanes and at turns, and lane movement restrictions. A lane-based network overcomes the limitations by maintaining lanes as independent topological objects and thus supports data management, decision making, and network analysis at the lane level. The data model for a lane-based network uses a directed graph approach in which a set of unidirectional lanes and nodes is used to model traffic flow connectivity. The model manages the continuous lateral connectivity between parallel lanes by specifying the relative lateral position of the lanes on their parent roadways. This approach provides an efficient way to maintain lane topology and eliminates the requirement of turntables. This paper presents the model along with guidelines for lane-based inventory management and strateg...

The strength of Mac Lane set theory

Saunders Mac Lane has drawn attention many times, particularly in his book Mathematics: Form and Function, to the system ZBQC of set theory of which the axioms are Extensionality, Null Set, Pairing, Union, Infinity, Power Set, Restricted Separation, Foundation, and Choice, to which system, afforced by the principle, TCo, of Transitive Containment, we shall refer as MAC. His system is naturally related to systems derived from topos-theoretic notions concerning the category of sets, and is, as Mac Lane emphasises, one that is adequate for much of mathematics. In this paper we show that the consistency strength of Mac Lane's system is not increased by adding the axioms of Kripke–Platek set theory and even the Axiom of Constructibility to Mac Lane's axioms; our method requires a close study of Axiom H, which was proposed by Mitchell; we digress to apply these methods to subsystems of Zermelo set theory Z, and obtain an apparently new proof that Z is not finitely axiomatisable; we study Friedman's strengthening KP P + AC of KP+ MAC , and the Forster–Kaye subsystem KF of MAC, and use forcing over ill-founded models and forcing to establish independence results concerning MAC and KP P ; we show, again using ill-founded models, that KP P +V = L proves the consistency of KP P ; turning to systems that are type-theoretic in spirit or in fact, we show by arguments of Coret and Boffa that KF proves a weak form of Stratified Collection, and that MAC+ KP is a conservative extension of MAC for stratified sentences, from which we deduce that MAC proves a strong stratified version of KP ; we analyse the known equiconsistency of MAC with the simple theory of types and give Lake's proof that an instance of Mathematical Induction is unprovable in Mac Lane's system; we study a simple set theoretic assertion—namely that there exists an infinite set of infinite sets, no two of which have the same cardinal—and use it to establish the failure of the full schema of Stratified Collection in Z; and we determine the point of failure of various other schemata in MAC. The paper closes with some philosophical remarks.

A continuum theory of traffic dynamics for freeways with special lanes

This paper presents a generalized theory of kinematic waves for freeways with two vehicle types and a set of lanes reserved for one of the vehicle classes. The theory is not restricted to freeways on which the special lanes are clearly identified by signs and pavement markings; e.g. for high occupancy vehicles. It may also apply if the restrictions are self-imposed, such as would occur on a freeway segment upstream of a busy off-ramp where the existing traffic naturally avoids the ‘far-side’ lanes. Of particular interest are oversaturated time periods because the original theory of kinematic waves proposed by Lighthill and Whitham [Proceedings Royal Society, A229, 281–345 (1955)] and Richards (1956) does not recognize that different traffic conditions (queues and speeds) may arise on the two sets of lanes, and that these may affect the two vehicle classes in different ways. It should be intuitive that whether a single coalesced queue forms on both sets of lanes or separate queues form on each set should depend on the traffic composition by vehicle class. In an attempt to furnish a reasonable depiction of these phenomena, a pair of conservation-type partial differential equations in the densities of the two vehicle types is used to model the freeway. In their simplest form, the equations only require the introduction of one additional parameter (representing the fraction of lanes allocated to each vehicle type) over the basic kinematic wave theory. The model is attractive because the nature of its solution can be described in complete physical detail by means of simple intuitive diagrams that show how the simple kinematic wave model is improved. The paper also introduces an exact solution method for problems with piece-wise constant initial data that can either be applied graphically or numerically. For general (piece-wise smooth) data, the numerical technique can be used to approximate the true solution as closely as desired in a way that does not deteriorate with time. A less precise finite-difference approach that always moves vehicles forward is also presented.