Traffic Operations: Introduction to Traffic Modelling

<p>Hydrodynamic modelling</p> Signup and view all the answers

<p>Delays due to interactions between vehicles</p> Signup and view all the answers

<p>Studying interactions between vehicles on a microscopic level</p> Signup and view all the answers

<p>Direct and unbiased measurement of traffic density and vehicle trajectories</p> Signup and view all the answers

<p>Complex vehicle tracking algorithms</p> Signup and view all the answers

<p>FCD records the spatiotemporal location of all vehicles while trajectory data only collects data on a few probe vehicles</p> Signup and view all the answers

<p>A transponder on the vehicle, a tag reader antenna, and a host computing system</p> Signup and view all the answers

<p>At high flow levels, congestion is experienced causing a decrease in vehicle flow</p> Signup and view all the answers

<p>Bluetooth signals of mobile phones</p> Signup and view all the answers

<p>GPS receivers of probe vehicles</p> Signup and view all the answers

<p>(ℎ𝑖 ) Spacing between two GPS points divided by the respective time instances</p> Signup and view all the answers

<p>Position of gas/brake pedals, turning signals, angle of steering wheel</p> Signup and view all the answers

<p>Load passing through a specific location during a period 𝑇</p> Signup and view all the answers

<p>Spatial observation = Observer records traffic variables over a road segment at a specific time Observation in movement = Observer enters the traffic stream to record traffic variables Temporal observation = Observer standing in a specific point records traffic variables during a period of time Traffic flow theory = Modelling traffic as a stream and studying traffic variables aggregately</p> Signup and view all the answers

<p>Hydrodynamic modelling = Traffic is modelled as a stream and variables are studied aggregately Car following modelling = Deals with interactions between vehicles on a microscopic level Uninterrupted traffic flow = Traffic flows in highway segments without compulsory stops, allowing for speed changes and full stops due to vehicle interactions Interrupted traffic flow = Deals with traffic interrupted by intersections, stations, bus stops, or parking facilities, focusing on delays, queues, and externalities like congestion and pollution</p> Signup and view all the answers

<p>Bluetooth readers = Allows for precise identification of individual vehicles and their movements Floating car observation = Provides real-time data on vehicle movements and traffic conditions Automatic Vehicle Identification (AVI) = Enables electronic toll collection and efficient vehicle tracking Camera-based data collection = Offers detailed visual information about traffic patterns and behaviors</p> Signup and view all the answers

<p>Floating car data (FCD) = Data collected from vehicles equipped with GPS or other tracking devices Extended Floating Car Data (xFCD) = Includes additional information such as vehicle speed, acceleration, and fuel consumption Trajectory data from cameras = Information derived from visual recordings of vehicle movements Headway = The time gap or distance between a vehicle and the one in front of it</p> Signup and view all the answers

<p>Traffic flow (𝑞) = Measures the rate of flow of vehicles through a given point or section of roadway over time Speed-flow relationship = Describes the correlation between vehicle speed and traffic flow under continuous circulation Interrupted traffic = Deals with traffic interrupted by intersections, stations, bus stops, or parking facilities Car following modelling focus = Mainly concerned with interactions between vehicles on a microscopic level</p> Signup and view all the answers

<p>Automatic Vehicle Identification (AVI) = Enables precise identification of vehicles for electronic toll collection purposes Electronic Toll Collection (ETC) = Facilitates automatic payment of tolls without requiring vehicles to stop at toll booths Bluetooth readers = Allow for seamless identification of individual vehicles and their movements Camera-based data collection methods = Provide detailed visual information about traffic patterns and behaviors</p> Signup and view all the answers

<p>Camera-based data collection = Direct and unbiased measurement of traffic density Floating Car Data (FCD) = Collects data on a few probe vehicles Automatic Vehicle Identification (AVI) based on an electronic toll collection (ETC) system = Consists of a transponder on the vehicle Bluetooth Readers = Recognize passing traffic using Bluetooth signals of mobile phones</p> Signup and view all the answers

<p>Trajectory data from cameras = Extracts vehicle trajectories 𝑥𝑎 (𝑡) Floating Car Data (FCD) = Derived from GPS receivers of probe vehicles and processed with map-matching algorithms Automatic Vehicle Identification (AVI) based on an electronic toll collection (ETC) system = Based on an electronic toll collection system Bluetooth Readers = Recognize passing traffic using Bluetooth signals of mobile phones</p> Signup and view all the answers

<p>Flow (𝑞) = The number of physical units 𝑛 that pass through a specific location during a period 𝑇 Headway (ℎ𝑖 ) = The time interval between two consecutive vehicles passing a point Instantaneous speed 𝑣(𝑡) = The derivative of the trajectory at a point 𝑡0 Extended floating car data (xFCD) = Includes additional information such as gas/brake pedals, turning signals, angle of steering wheel</p> Signup and view all the answers

<p>Car following modeling = Deals with interactions between vehicles on a microscopic level Continuous traffic flow modeling = Models oriented towards delays, queues, and externalities such as congestion and pollution Interrupted traffic flow modeling = Deals with traffic interruptions such as traffic signals and stop signs Aggregate traffic flow modeling = Models traffic as a stream and studies traffic variables aggregately</p> Signup and view all the answers

<p>Covers small road section = A few hundred meters at most Expensive = Requires mounting camera(s) on top of tall building, airplane or drone Complex vehicle tracking algorithms = Required for camera-based methods Errorprone = Associated with complex vehicle tracking algorithms</p> Signup and view all the answers

<p>Gas/brake pedals, turning signals, angle of steering wheel = Additional information included in xFCD GPS points divided by time instances = Used to derive speed of a probe vehicle Position of GPS receivers of probe vehicles processed with map-matching algorithms = Method used to collect FCD Direct and unbiased measurement of traffic density, vehicle trajectories, and lane changes = Main advantage of camera-based methods</p> Signup and view all the answers

<p>Transponder on the vehicle = (1) Part of AVI system Tag reader antenna at each toll lane = (2) Part of AVI system Host computing system = (3) Part of AVI system Mobile phones = (Primarily) recognized by Bluetooth readers</p> Signup and view all the answers

<p>Speed 𝑣(𝑡) = Instantaneous speed derived from the trajectory at a point 𝑡0 Flow (𝑞) = Number of physical units passing through a specific location during a period 𝑇 Headway (ℎ𝑖 ) = The time interval between two consecutive vehicles passing a point Congestion state = Experienced when flow decreases at a certain level</p> Signup and view all the answers

<p>Continuous circulation theory = Depicts relationship between speed and flow under continuous circulation Congestion theory = Describes how congestion leads to decreased vehicle flow Car interaction theory = Deals with interactions between vehicles on a microscopic level Aggregate flow theory = Models oriented towards delays, queues, and externalities such as congestion and pollution</p> Signup and view all the answers

<p>Collects data on a few probe vehicles = Difference from trajectory data derived from cameras Does not record which lane a vehicle is using = Difference from trajectory data derived from cameras Derived from GPS receivers of probe vehicles and processed with map-matching algorithms = Method used to collect FCD Records spatiotemporal location of all vehicles within a given road segment and time interval = Difference from FCD</p> Signup and view all the answers