Remote road traffic data collection and intelligent vehicle highway system

Claim 3

A method as claimed in claim 1 further comprising the steps of: (e) repeating steps (c) and (d) to calculate an average travel time T 2 for a link L 2 at a time (t+T 1 ), an average travel time T 3 for a link L 3 at a time (t+T 1 +T 2 ) sequentially up to an average travel time Tn for a link Ln at a time (t+T 1 +T 2 + . . . +Tn−1); and (f) calculating an average travel time T R for a route R including continuous links L 1 , L 2 , L 3 , . . . and Ln at the departure time t by summing the average travel times T 1 , T 2 , T 3 , . . . and Tn for predicting a travel time for route R at the departure time t on the day D.

Claim 4

A method as claimed in claim 2 wherein the route R including critical left-turns and left-turn waiting time is added to the travel time of route R.

Claim 5

A method as claimed in claim 2 wherein the predicted travel time T 1 for the link L 1 at the time t on the day D is forecasted by: (a) repeating steps (c) and (d) to calculate travel times Tw 1 , Tw 2 , . . . and Twm for the link L 1 at the given time t on the given day D of weeks w 1 , w 2 , . . . wm; and (b) averaging Tw 1 , Tw 2 , . . . Twm to determine T 1 .

Claim 6

A method as claimed in claim 4 wherein a weighted average method is used for averaging Tw 1 , Tw 2 , . . . Twm.

Claim 7

A method as claimed in claim 5 wherein the day D is in a week immediately following week Tw 1 , where Tw 1 is the most recent week and a series of decreasing weighting factors are applied in the weighted average method, so that the travel times for more recent weeks affect the forecast more than travel times for weeks further in the past.

Claim 8

A method as claimed in claim 2 wherein the average travel time for route R at the departure time t on the given day D of the week is converted to an average travel speed on the route R.

Claim 9

A method as claimed in claim 1 wherein the given time interval in step (c) is selected from time intervals which are predetermined equal intervals of the day D.

Claim 10

A method as claimed in claim 1 wherein the average travel time T 1 for the link L 1 at the time t on the given day D of the week w is converted to an average travel speed on link L 1 .

Claim 11

A method as claimed in claim 1 wherein the predicted travel time is multiplied by a predetermined weighting factor associated with road or weather conditions to adjust the predicted travel time for link L 1 at the time t on the day D when the road or weather conditions are abnormal, and/or adjusted by current unusual congestion.

Claim 12

A method as claimed in claim 1 wherein the reporting interval RI is an integer multiple of the collection interval CI.

Claim 13

A method as claimed in claim 1 wherein the digitized road network is broadcast from the traffic service center to the vehicles via a radio frequency broadcast of digital data, and the broadcast is received by radio frequency receivers in the equipped vehicles.

Claim 14

A method as claimed in claim 12 wherein the radio frequency broadcast of digital data is performed at predetermined time intervals and includes node information, link information and left-turn information.

Claim 15

A method as claimed in claim 12 wherein a one-way road in the digitized road network is represented by a continuous series of the links oriented in a traffic direction and a two-way road in the digitized road network is represented by a continuous series of pairs of oppositely oriented, parallel links, each pair of links connecting two adjacent nodes.

Claim 16

A method as claimed in claim 1 wherein a reference system for the digitized road network is the same as a reference system used by the global positioning system.

Claim 17

A method as claimed in claim 1 wherein each of the links is referenced by computing an angle of rotation from a source node of the link with respect to an imaginary link oriented due east from the source node, the slope angle being represented as a positive angle if the link is in an upper quadrant with respect to the imaginary link and as a negative angle if the position link is in a lower quadrant with respect to the imaginary link, the slope angle of the link being in a range of 0° to ±180°.

Claim 18

A method as claimed in claim 16 wherein a position of each of the vehicles on the digitized road network is computed by performing steps of: (a) receiving at the vehicle current global positioning information from a plurality of satellites of the global positioning system; (b) locating a geographical position of the vehicle on the digitized road network using the global positioning information; (c) locating on the digitized road network a last node passed by the vehicle and computing a distance between the geographical position and the last node passed; (d) creating a position link between the last node passed and the geographical position of the vehicle on the digitized road network; (e) determining a slope angle of the position link by computing an angle of rotation between the position link and an imaginary link oriented towards due east from the last node passed; (f) comparing the slope angle of the position link with a slope angle of each link emanating from the last node passed, and selecting a link having a slope angle with an absolute value nearest an absolute value of the slope angle of the position link; and (g) relocating the geographical position of the vehicle to the selected link at a distance from the last node passed equal to a distance between the geographical position and the last node passed.

Claim 19

A method as claimed in claim 17 wherein a start point of an equipped vehicle begiining a trip is located by the steps of: (a) receiving current global positioning information at the equipped vehicle from the global positioning system; (b) computing a current geographical position of the quipped vehicle and locating the position on the digitized road network as the start point; (c) selecting a node on the digitized road network that is closest to the start point; and (d) moving the start point to the selected node which thereafter serves as the last node passed for locating a next vehicle position on the digitized road network.

Claim 20

A method as claimed in claim 18 wherein the start point of the vehicle is located by performing the following steps between the steps (c) and (d): (1) comparing a distance between the current geographical position of the equipped vehicle and the selected node to a predetermined distance; and (2) repeating steps (a) to (c) if the distance between the current geographical position and the selected node is greater than the predetermined distance, until a distance between the current geographical position and a selected node is smaller than the predetermined distance, and moving the start point to the selected node.

Claim 21

A method as claimed in claim 17 wherein the geographical position of the vehicle on the digitized road network is computed by performing further steps of: comparing a distance between the current geographical position of the equipped vehicle and a last known node with a length of the selected link; and moving the current geographical position on the selected link to a sink node of the selected link if a difference between a length of the selected link and the distance is smaller than a predetermined distance, or retaining the current geographical position on the link if the difference is greater than the predetermined distance.

Claim 22

A remote traffic data collection and intelligent vehicle highway system for a highway vehicle, comprising: a traffic service center adapted to receive and process vehicle position data to determine an average travel time or travel speed for any specific link during a given forecast interval on a given day of a week, and broadcast a digitized road network consisting of nodes interconnected by straight links representing road segments, the links indicating traffic direction between the nodes, and to concurrently, or independently broadcast a forecast of an average travel time or travel speed for the specific link during the given forecast interval on the given day in the future; a remote traffic data collection sub-system including in-vehicle devices in a plurality of vehicles, each of the devices being adapted to receive, from time to time, global positioning information from a Global Positioning System (GPS) and to convert the global positioning information into the vehicle position data associated with at least some of the nodes on the digitized road network, the global positioning information being received and converted into the vehicle position data at a predetermined collection interval (CI); and a communication sub-system in each device and the traffic service center for communicating the vehicle position data from the vehicle to the traffic service center, and the digitized road network and the road traffic forecast from the traffic service center to the vehicle, the vehicle position data being reported to the traffic service center at a predetermined reporting interval (RI), wherein RI>CI.

Claim 23

A remote traffic data collection and intelligent vehicle highway system for a highway vehicle, comprising: a traffic service center adapted to receive and process vehicle position data to determine an average travel time or travel speed for any specific link during a given forecast interval on a given day of a week, and broadcast a digitized road network consisting of nodes interconnected by straight links representing road segments, the links indicating traffic direction between the nodes, and to concurrently, or independently broadcast a forecast of an average travel time or travel speed for the specific link during the given forecast interval on the given day in the future; a remote traffic data collection sub-system including in-vehicle devices in a plurality of vehicles, each of the devices being adapted to receive, from time to time, global positioning information from a Global Positioning System (GPS) and to convert the global positioning information into the vehicle position data associated with at least some of the nodes on the digitized road network, the global positioning information being received and converted into the vehicle position data at a predetermined collection interval (CI); and a communication sub-system in each device and the traffic service center for communicating the vehicle position data from the vehicle to the traffic service center, and the digitized road network and the road traffic forecast from the traffic service center to the vehicle, the vehicle position data being reported to the traffic service center at a predetermined reporting interval (RI), wherein RI>CI.

Claim 24

A system as claimed in claim 21 wherein the traffic service center comprises: a highway vehicle database for storing the vehicle position data received from equipped vehicles travelling roads in a service area; a traffic forecaster program for processing the vehicle position data and to derive an average travel time T 1 for a link L 1 during a given forecast interval (FI); a server for executing the traffic forecaster program and storing the digitized road network; and a data exchange interface for connecting the server to a communication sub-system which transmits the traffic forecast data respecting average travel times for links and receives the vehicle data dynamically reported from each of the equipped vehicles travelling roads in the service area.

Claim 25

A system as claimed in claim 22 wherein the traffic service center comprises an external party interface adapted to connect to external parties for road and weather information, and an external party integrator adapted to integrate the road and weather information with the traffic forecast data.

Claim 26

A system as claimed in claim 21 wherein each of the in-vehicle devices comprises: a global positioning system receiver for receiving global positioning information from satellites of the global positioning system; a mobile radio sub-system adapted to transmit vehicle location data to the traffic service center and receive traffic forecast data from the traffic service center; a driver interface to permit a driver of the vehicle to interact with the in-vehicle device; an emergency reporting mechanism; and a vehicle support system including: a computer system for executing a vehicle position locator program, storing the digitized road network received from the traffic service center and other data, as required, and the vehicle position locator program for determining a location of the vehicle on the digitized road network using the global positioning information.

Claim 27

A system as claimed in claim 24 wherein the vehicle support system further comprises a road explorer program executed by the computer system, adapted to provide route information using the traffic forecast data.

Claim 28

A system as claimed in claim 25 wherein the driver interface includes a data entry mechanism adapted to enable the driver to enter a destination point, and a display mechanism for displaying a recommended travel route between a departure point and the destination point.

Claim 29

A system as claimed in claim 26 wherein the road explorer computes a predicted travel time for a route using predicted travel times for links which form the route.

Claim 32

A method as claimed in claim 28 wherein the nearest link associated with the node which the vehicle last passed is determined by: retrieving or determining a slope angle of each link that emanates from the last node passed, the respective slope angles being determined by computing an angle of rotation between each link and an imaginary link oriented due east from the node, the slope angle being represented as a positive angle if the link is in an upper quadrant with respect to the imaginary link and as a negative angle if the link is in a lower quadrant with respect to the imaginary link, the slope angle of the link being an angle between 0° and ±180°; creating a position link from the node last passed by the vehicle and the geographical position of the vehicle on the digitized road network; determining a slope angle of the position link by computing an angle of rotation between the position link and the imaginary link; comparing the slope angle of the position link with the respective slope angles of each link emanating from the node respectively, and selecting one of the links having a slope angle with an absolute value closest to an absolute value of the slope angle of the position link.

Claim 33

A method as claimed in claim 28 further comprising steps of: receiving current global positioning information at the equipped vehicle from time to time from a global positioning system; repeating the steps for locating an equipped vehicle position on the digitized road network until the position of the equipped vehicle is located on the digitized road network.

Claim 34

A method as claimed in claim 28 wherein a start node for the equipped vehicle is located by steps of: (a) receiving current global positioning data at the equipped vehicle from the global positioning system; (b) computing the current geographical position of the equipped vehicle and locating the geographical position on the digitized road network as a start point; (c) selecting a node on the digitized road network that is closest to the start point; and (d) moving the start point to the selected node, whereby the node series as a node last passed by the equipped vehicle for locating a following vehicle position on the digitized road network.

Claim 35

A method as claimed in claim 31 wherein the start node of the vehicle is located by performing further steps between the steps (c) and (d), the further steps comprising: (1) comparing a distance between the start point and the selected node with a predetermined distance; and (2) repeating Steps (a) to (c) if the distance between the start point and the selected node is greater than the predetermined distance, until a distance between the start point and the selected node is less than the predetermined distance.

Claim 36

A method as claimed in claim 28 wherein the equipped vehicle is located on the digitized road network by further steps of: comparing a length of the position link with a length of the selected link; and further moving the geographical position on the selected link to the sink node of the selected link if the difference in length between the selected link and the position link is less than a predetermined distance, and retaining the geographical position on the link if the difference is greater than the predetermined distance.