Traffic control system

• US 5,646,853 A
• Filed: 07/16/1992
• Issued: 07/08/1997
• Est. Priority Date: 07/19/1991
• Status: Expired due to Fees

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Nagai, Tohru, Hamada, Nobuhiro, Suzuki, Toshiko, Takahashi, Kazunori, Takatoo, Masao
• Primary Examiner(s): ZANELLI, MICHAEL J
• Application Number:
  US07/913,902
• Time in Patent Office: 1,818 Days
• Field of Search: 364/436, 364/437, 364/578, 340/990, 340/992, 340/911, 340/915, 340/920, 340/910, 340/917, 348/148, 348/149
• US Class Current: 455/456.5
• CPC Class Codes: G08G 1/08 according to detected number or speed of vehicles

Abstract

A traffic control system having a road information storing unit for storing information of a road map and the capacity of roads on the road map, a traffic measuring unit for measuring the traffic of roads, a traffic increase/decrease quantity calculating unit for calculating a traffic increase/decrease quantity between main points by using the measured traffic, a road traffic calculating unit for calculating traffic of a main road, by using the traffic increase/decrease quantity, and an area determining unit for determining an area which is the area for congestions less traffic by using the calculated traffic and the road capacity while maintaining the traffic increase/decrease quantity at a proper value. It is possible to control the traffic while considering nearby traffic conditions, to prevent and relieve congestion, and to maximize the traffic of roads, thereby minimizing the time required for reaching a destination.

Claims

1. A vehicle guidance system for guiding a vehicle on a road to a bypath road, comprising:

target traffic setting means for setting target traffic of the bypath road;

real-time traffic measuring means for measuring traffic of said bypath road in real-time;

instruction means for supplying an instruction to the vehicle to avoid traffic congestion of said road; and

guidance control means for controlling said instruction means so as to reduce a difference between said target traffic and said real-time traffic.

2. A vehicle guidance system according to claim 1, wherein said guidance control means controls said instruction means to distribute part of said traffic on said road to said bypath road.

3. A vehicle guidance system according to claim 1, wherein said instruction means includes a traffic signal.

4. A vehicle guidance system according to claim 1, wherein said instruction means includes a display device for displaying a bypath road.

5. A vehicle guidance system according to claim 1, wherein said real-time traffic measuring means measures traffic by receiving a signal from a transmitting apparatus mounted on a vehicle.

6. A vehicle guidance system for guiding a vehicle on a road to a bypath road, comprising:

target traffic setting means for setting target traffic of the bypath road;

real-time traffic measuring means for measuring the traffic of said bypath road in real-time;

traffic estimating means for estimating the traffic of said bypath road by using said real-time traffic;

instruction means for supplying an instruction to a vehicle to avoid traffic congestion of said road; and

guidance control means for controlling said instruction means so as to reduce a difference between said target traffic and said real-time traffic.

7. A vehicle guidance system according to claim 6, wherein said traffic estimating means includes past data storage means for storing past traffic data, retrieving means for retrieving said past traffic data nearest said real-time traffic by comparing said real-time traffic with said past traffic data, said retrieved past traffic data being used as estimated traffic.

8. A vehicle guidance system according to claim 6, wherein said traffic estimating means includes a simulator for estimating the traffic of said bypath road by using said real-time traffic and road capacity as parameters.

9. A vehicle guidance system according to claim 8, further comprising right/left turn percentage measuring means for measuring a right/left turn percentage of vehicles at an intersection, said simulator estimating the traffic by using said right/left turn percentage.

10. A vehicle instructing and controlling system for controlling traffic, comprising:

instruction means for supplying a traffic instruction to indicate a route to a vehicle;

real-time traffic measuring means for measuring traffic of a road in real-time;

a simulator external to said vehicle for estimating a vehicle wait time by using said instruction supplied by said instruction means and said real-time traffic; and

a controller for controlling said instruction means so as to reduce a sum of said estimated wait times multiplied by predetermined weighted coefficients for said vehicle.

11. A vehicle instructing and controlling system according to claim 10, wherein said instruction means includes a traffic signal, and said controller includes a traffic signal parameter controller for controlling the parameters of said traffic signal.

12. A vehicle instructing and controlling system according to claim 10, wherein said instruction means includes a display device for guiding a vehicle, and said controller includes a display content controller for changing the display contents of said display device.

13. A vehicle instructing and controlling system according to claim 10, wherein said real-time traffic measuring means measures the traffic by receiving a signal from a transmitting apparatus mounted on a vehicle.

14. A vehicle instructing and controlling system according to claim 10, further comprising right/left turn percentage measuring means for measuring a right/left turn percentage of vehicles at an intersection, said simulator estimating the traffic by using said right/left turn percentage.

15. A traffic control system, comprising:

means for receiving parameters of traffic signals on a road;

traffic measuring means for measuring traffic in real-time;

a simulator for estimating traffic by using the parameters of said traffic signals and said real-time traffic;

calculating means for calculating a difference between said estimated traffic and, actual traffic at the time corresponding to said estimated traffic;

instruction means for providing an indication of a road point at which said difference becomes equal to or larger than a predetermined value; and

display means responsive to an instruction by said instruction means for displaying said road point and an indication of an occurrence of an accident at said road point.

16. A traffic control system according to claim 15, further comprising right/left turn percentage measuring means for measuring a right/left turn percentage of vehicles at an intersection, said simulator estimating the traffic by using said right/left turn percentage.

17. A traffic control system, comprising:

traffic difference calculating means for calculating a difference between integrated traffic at opposite ends of a road section having traffic measuring means at the opposite ends;

intermediate inflow/outflow traffic calculating means for calculating an intermediate inflow/outflow traffic going into or coming from another road section connected to an intermediate point of said road section exclusive of said traffic measuring points, by using said integrated traffic difference; and

control means for suppressing said inflow traffic of a branch road within said road section.

18. A traffic control system comprising:

means for detecting outflow traffic to one road whose traffic is to be controlled, from an intersection having three or more roads;

means for detecting inflow traffic to said one road from each of other roads different from said one road, to thereby control the inflow traffic;

means for setting allowable traffic of said one road to be controlled based on the detected inflow traffic;

means, connected to said outflow traffic detecting means and said setting means, for comparing said outflow traffic with said allowable traffic, and sensing an occurrence of a saturated traffic condition of said one road to be controlled; and

suppressing means, connected to said comparing and sensing means and responsive to an occurrence of said saturated traffic condition, for suppressing said inflow traffic to said one road from at least one of said other roads,

wherein said suppressing means suppresses said inflow traffic to said one road from said at least one other road, at an intersection upstream of said intersection, to increase the number of intersections at which said inflow traffic is suppressed and to expand a traffic control area.

19. A traffic control system according to claim 18, wherein said suppressing means suppresses said inflow traffic to said one road from said at least one other road, sequentially at upstream intersections to expand the traffic control area, until said saturated traffic condition is released.

20. A traffic control system according to claim 18, wherein said suppressing means includes indication means for indicating a bypath road for guiding traffic at said intersection to an intersection downstream of said one road to be controlled.

21. A traffic control system comprising:

means for detecting overflow traffic to one road whose traffic is to be controlled, from an intersection having three or more roads;

means for detecting inflow traffic to said one road from each of other roads different from said one road to be controlled;

means for setting allowable traffic of said one road to be controlled based on the detected inflow traffic;

means connected to said outflow traffic detecting means and said setting means, for comparing said outflow traffic with said allowable traffic, and estimating an occurrence of a saturated traffic condition of said one road to be controlled; and

means connected to said estimating means and responsive to an estimation of an occurrence of said saturated traffic condition, for suppressing said inflow traffic to said one road from at least one of said other roads,

wherein said suppressing means suppresses said inflow traffic to said one road from said at least one other road, at an intersection upstream of said intersection, to increase the number of intersections at which said inflow traffic is suppressed and to expand a traffic control area.

22. A traffic control system according to claim 21, wherein said suppressing means suppresses said inflow traffic to said one road from said at least one other road, sequentially at upstream intersections to expand the traffic control area, until said saturated traffic condition is released.

23. A traffic control system according to claim 21, wherein said suppressing means includes indication means for indicating a bypath road for guiding traffic at said intersection to an intersection downstream of said one road to be controlled.

24. A traffic control system, comprising:

means for detecting outflow traffic to one road whose traffic is to be controlled and traffic of at least two bypath roads, said one road and said at least two bypath roads constituting a traffic control area;

means for setting allowable traffic of said one road to be controlled;

means for setting target traffic of said at least two bypath roads;

first means connected to said detecting means and said allowable traffic setting means, for comparing said outflow traffic to said one road to be controlled with said allowable traffic, and sensing an occurrence of a saturated traffic condition of said one road to be controlled;

indication means connected to said first comparing and sensing means and responsive to an occurrence of said saturated traffic condition, for indicating one of said at least two bypath roads to vehicles going toward said one road to be controlled;

second means connected to said detecting means and said allowable traffic setting means, for comparing actual traffic of said indicated bypath road with said target traffic, and sensing an occurrence of a saturated traffic condition of said indicated bypath road; and

indication controlling means connected to said second comparing and sensing means and said indication means and responsive to an output from said second sensing means, for prompting said indication means to indicate another bypath road of said at least two bypath roads.

25. A traffic control system, comprising:

means for detecting outflow traffic to one road whose traffic is to be controlled and traffic of at least two bypath roads, said one road and said at least two bypath roads constituting a traffic control area;

means for setting allowable traffic of said one road to be controlled;

means for setting target traffic of said at least two bypath roads;

first means connected to said detecting means and said allowable traffic setting means, for comparing said outflow traffic to said one road to be controlled with said allowable traffic, and estimating an occurrence of a saturated traffic condition of said one road to be controlled;

indication means connected to said first detecting and estimating means and responsive to an occurrence of said saturated traffic condition, for indicating one of said at least two bypath roads to vehicles going toward said one road to be controlled;

second means connected to said detecting means and said allowable traffic setting means, for comparing the actual traffic of said indicated bypath road with said target traffic, and estimating an occurrence of a saturated traffic condition of said indicated bypath road; and

indication controlling means connected to said second comparing and estimating means and said indication means and responsive to an output from said second comparing and estimating means, for prompting said indication means to indicate another bypath road of said at least two bypath roads.

26. A traffic control system having indication means for an operator'"'"'s usage, comprising:

road information storing means for storing information of a road map and a capacity of respective roads on said road map;

traffic measuring means for measuring traffic of said respective roads;

traffic increase/decrease quantity calculating means for calculating a traffic increase/decrease quantity between predetermined points, by using said measured traffic;

road traffic calculating means for calculating traffic of a predetermined road, by using said traffic increase/decrease quantity;

area determining means for determining an area which is an area for congestionless traffic, by using said calculated traffic and said road capacity while maintaining said traffic increase/decrease quantity to a proper value; and

means for prompting said indication means to indicate the area for congestionless traffic.

27. A traffic control system according to claim 26, further comprising:

available traffic calculating means for calculating maximum traffic allowed to enter said area without congesting said area; and

area traffic suppressing means for suppressing traffic moving toward said area in accordance with said maximum traffic.

28. A traffic control system according to claim 27, further comprising:

traffic signals set using variable parameters in response to said available traffic calculation means and said area traffic suppressing means; and

traffic signal parameter setting means for setting the parameters of said traffic signals to regulate the variable traffic.

29. A traffic control system according to claim 27, further comprising information supplying means for supplying information to vehicles outside said area, and wherein said area traffic suppressing means includes instruction means for instructing said information supplying means outside said area to supply the boundary of said area, information of suppressing said maximum traffic allowed, and an indication of bypassing said area, either singularly or in combination thereof.

30. A traffic control system according to claim 29, wherein said information supplying means includes a display device installed on a road.

31. A traffic control system according to claim 29, wherein said information supplying means includes a display device mounted on a vehicle.

32. A traffic control system according to claim 29, wherein said information supplying means includes wireless receiving means mounted on a vehicle and transmitting means for transmitting radio waves to said wireless receiving means.

33. A traffic control system according to claim 28, wherein said area traffic suppressing means includes instruction means for instructing said traffic signal parameter setting means to set the variable parameters of said traffic signals outside said area to suppress the traffic moving toward said area.

34. A traffic control system according to claim 28, wherein said area traffic increasing means includes instructing means for instructing said traffic signal parameter setting means to set the variable parameters of said traffic signal within said area to increase the traffic within said area.

35. A traffic control system according to claim 26, further comprising area traffic increasing means for controlling an increase of traffic within said area.

36. A traffic control system according to claim 35, further comprising information supplying means for supplying information to vehicles within said area, and wherein said area traffic increasing means includes instruction means for instructing said information supplying means within said area to supply the boundary of said area, prohibition of parking/stopping within said area, and an indication of bypassing a congested road within said area and moving to another road within said area, either singularly or in combination thereof.

37. A traffic control system according to claim 36, further comprising a parking system installed on a parking area near a road, said parking system detects a parked/stopped vehicle to indicate a violation of the prohibition thereof and includes display means for displaying the detected results and notifying vehicles on a road of the detected results.

38. A traffic control system according to claim 37, wherein said area traffic increasing means indicates to said display means of said parking system within said area to display an indication of the parking/stopping prohibition, and said display means displays said parking/stopping prohibition.

39. A traffic control system according to claim 26, wherein said traffic measuring means includes light radiating means for radiating one of a slit light beam and a spot light beam to the body of a vehicle, and an image receiving apparatus for receiving a reflected light beam from said vehicle at an angle different from the angle of said radiated beam.

40. A traffic control system according to claim 26, wherein said traffic measuring means measures traffic by receiving a signal from a transmitting apparatus mounted on a vehicle.