TRAFFIC FLOW MONITORING FOR INTERSECTIONS WITH SIGNAL CONTROLS
First Claim
1. A method comprising:
- retrieving vehicle detector data and traffic control signal data for a signalized intersection, the vehicle detector data detecting the passing of at least one vehicle;
assigning an initial position for a virtual probe; and
a processor updating a position and a velocity for the virtual probe such that the position and velocity of the virtual probe is determined multiple times from a time when the virtual probe is at the initial position until a time when the updated position of the virtual probe is past a stop line of the intersection.
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Accused Products
Abstract
A method and system are provided for determining travel time through intersections by assigning an initial position for a virtual probe in the intersection and updating the position and velocity for the virtual probe such that the position and velocity of the virtual probe are determined multiple times from a time when the virtual probe is at an initial position until the time when the updated position of the virtual probe is past a stop line at the intersection. Updating the position and velocity of the virtual probe involves retrieving vehicle detection data and traffic control signal data to determine a distance from the virtual probe to the closer of a stop line and a vehicle in a queue in front of the virtual probe. The length of the queue is determined using the intersection of two shockwaves.
46 Citations
40 Claims
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1. A method comprising:
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retrieving vehicle detector data and traffic control signal data for a signalized intersection, the vehicle detector data detecting the passing of at least one vehicle; assigning an initial position for a virtual probe; and a processor updating a position and a velocity for the virtual probe such that the position and velocity of the virtual probe is determined multiple times from a time when the virtual probe is at the initial position until a time when the updated position of the virtual probe is past a stop line of the intersection. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
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17. A computer-readable medium having computer-executable instructions that cause a processor to perform steps comprising:
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retrieving stored signal data and vehicle detector data for a signalized intersection; determining a position and velocity for a virtual probe that is not physically on the roadways; determining a separation distance from the virtual probe to the closer of a vehicle in front of the virtual probe and a stop line of the intersection based on the signal data and vehicle detector data; determining a safe space needed between the virtual probe and the closer of the vehicle in front of the virtual probe and the stop line; using the separation distance, the safe space, the position of the virtual probe and the velocity of the virtual probe to determine whether to change the velocity of the virtual probe; and using the position, the velocity and any change in velocity of the virtual probe to determine a new position and new velocity for the virtual probe. - View Dependent Claims (18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28)
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29. A method comprising:
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a processor determining a velocity of a discharge shockwave that starts at an intersection stop line and passes through a queue of vehicles located before the stop line; a processor determining a velocity of a departure shockwave that moves from the end of the queue toward the stop line; a processor using the velocity of the discharge shockwave and the velocity of the departure shockwave to determine a length of the queue of vehicles. - View Dependent Claims (30, 31, 32, 33, 34)
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35. A traffic monitoring system comprising:
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a vehicle detector sensor that senses a signal produced by a vehicle detector that generates the signal based on vehicles passing a detecting position located before an intersection; a signal state sensor that senses the state of a signal at the intersection; a storage unit that stores data corresponding to the signal of the vehicle detector and states of the signal sensed by the signal state sensor; a processor that receives data stored in the storage unit and that uses the received data to compute a length of a queue of vehicles at the intersection through steps comprising; determining the velocities of two shockwaves, each shockwave representing the motion of a discontinuity in a concentration of vehicles along a roadway leading to the intersection; and using the velocities of the two shockwaves to determine the length of the queue of vehicles. - View Dependent Claims (36, 37, 38, 39, 40)
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Specification