1. Field of the Invention
The present invention relates to a regional symmetric and interlocked traffic light control method, and more particularly to a regional traffic light control method for reducing traffic jams in a plurality of traffic jam control areas for at least two adjacent regions.
2. Description of the Related Art
Currently, traffic lights are commonly used for many intersection in metropolitan areas to control traffic for both vehicles and pedestrians.
A typical traffic light control method for a metropolitan area controls a series of traffic lights along the same direction for a predetermined distance to display a green light or a red light continuously. Therefore, regardless of the traveling speeds of any vehicle, it will have to stop at a red light, which increases travel times. Moreover, when a large number of vehicles all stop and wait for a red light, serious air and noise pollution problems are consequently generated, and which also causes traffic jams.
In order to control traffic at an intersection having two axial traffic directions, according to statistics, the vehicle on each street needs to spend at least half of its travel time waiting for red lights. Furthermore, in general, a typical car with a full tank of gas can run about 500 km on highways but only 220 km in cities; in other words, about 56% of the fuel is wasted, which is a tremendous waste of energy.
Therefore, it is desirable to provide a regional traffic light control method for reducing metropolitan traffic jams so as to mitigate and/or obviate the aforementioned problems.
An objective of the present invention is to provide a symmetric and interlocked regional traffic light control method, which can reduce vehicle travel times, air pollution, noise pollution, and wasted fuel.
In order to achieve the above-mentioned objectives, a regional symmetric and interlocked traffic light control method comprises:
(A) defining a first preferred point in a desired metropolitan area, and dividing the desired metropolitan area into a plurality of first axial streets and a plurality of second axial streets based on the first preferred point;
(B) determining a first axial average vehicle speed and a first axial preferred allowed travel time period for the first axial streets and a second axial average vehicle speed and a second axial preferred allowed travel time period for the second axial streets based on the first preferred point;
(C) obtaining a first vehicle travel distance according to the first axial average vehicle speed and the first axial preferred allowed travel time period and obtaining a second vehicle travel distance according to the second axial average vehicle speed and the second axial preferred allowed travel time period;
(D) determining a first control region according to the first preferred point, the first vehicle travel distance and the second vehicle travel distance, and including the first axial streets and the second axial streets in the first control region;
(E) defining a second preferred point and a third preferred point adjacent to the first control region;
(F) utilizing step (E) to determine a second control region adjacent to the first control region based on the second preferred point, and including the first axial streets in the first control region and the second control region;
(G) utilizing step (F) to determine a third control region adjacent to the first control region based on the third preferred point, and including the second axial streets in the first control region and the third control region, the three control regions forming a web;
(H) controlling a plurality of traffic lights in the first control region to display green lights to the vehicles traveling on the first axial streets and red lights to the vehicles traveling on the second axial streets according to the first axial preferred allowed travel time period, and controlling a plurality of traffic lights in the second control region and the third control region to display red lights to the vehicles traveling on the first axial streets and green lights to the vehicles traveling on the second axial streets according to the second axial preferred allowed travel time period; and
(I) linking the traffic lights in all the control regions by serializing.
Accordingly, vehicles traveling with the average vehicle speed move along the axial streets through the control region and the next control region. Therefore, when the vehicles in the control region move with the average vehicle speed they can all travel into another control region before the current allowing travel time period ends. In other words, vehicles in the control regions are able to travel through all connected control regions which can reduce vehicle travel times, air pollution, noise pollution, and wasted fuel.
The preferred point may be an intersection or a building.
The first axial streets and the second axial streets may be divided from the first preferred point based on a preferred direction.
The preferred direction may be geographic east, south, west or north.
The preferred direction may be the direction of the first axial streets or the second axial streets.
Other streets in the metropolitan area may be defined as a plurality of third axial streets; wherein when a third axial street is close to a first axial street, the third axial street is controlled in accordance with the first axial street, and when the third axial street is close to a second axial street, the third axial street is controlled in accordance with the second axial street.
The axial street may be a two-way street in which vehicles are not allowed to turn left. The axial streets may cross a plurality of sub-streets, such that the axial streets and the sub-streets are synchronized.
The vehicle average travel speed and the allowed travel time period for each control region may be identical, such that each control region has an identical size. Alternatively, the vehicle average travel speed and the allowed travel time period for each control region may be different, such that each control region has a different size.
The control region may be rectangular. The control regions may be aligned with the axial streets; or the control regions may be geographically aligned.
The traffic light may display a green light or a yellow light during the allowed travel time period.
A method further comprises: (J) defining a vehicle maximum speed limit Vmax based on the vehicle average travel speed and the following formula: Vmax=(1+A %)·V
wherein A % is a predetermined vehicle speed increasing ratio, which is defined according to road conditions; and V is the vehicle average travel speed.
Therefore, a symmetric and interlocked regional traffic light control method is provided for reducing metropolitan traffic jams to mitigate and/or obviate the aforementioned problems.
Other objects, advantages, and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.
Please refer to
In step S12, a first axial average vehicle speed V1 and a first axial preferred allowed travel time period t1 for the first axial streets 21, and a second axial average vehicle speed V2 and a second axial preferred allowed travel time period t2 for the second axial streets 22, are determined based on the first preferred point 31. The first and second axial average vehicle speeds V1, V2 are an average vehicle speed including a starting speed, an acceleration speed, a deceleration speed and a stop speed of the vehicles on the first axial streets 21 and the second axial streets 22 and which also includes a safety factor and a vehicle efficiency factor. The first and second axial preferred allowed travel time periods t1, t2 are allowed travel times on the first axial streets 21 and the second axial streets 22, and are determined based on current traffic loads. In this embodiment, the first and second axial average vehicle speeds V1, V2 are 60 km/hr, and the first and second axial preferred allowed travel time periods t1, t2 are 60 seconds.
In step S13, a first vehicle travel distance L1 is obtained according to the first axial average vehicle speed V1 and the first axial preferred allowed travel time period t1, and a second vehicle travel distance L2 is obtained according to the second axial average vehicle speed V2 and the second axial preferred allowed travel time period t2. In this embodiment, since the first and second axial average vehicle speeds V1, V2 are 60 km/hr and the first and second axial preferred allowed travel time period t1, t2 are 60 seconds, the first vehicle travel distance L1 and the second travel distance L2 will be 1 km.
In step S14, a first control region 11 is determined according to the first preferred point 31, the first vehicle travel distance L1 and the second vehicle travel distance L2, and the first axial streets 21 and the second axial streets 22 are included in the first control region 11. Since the first vehicle travel distance L1 and the second vehicle travel distance L2 are equal to each other, the first control region 11 is square in shape.
In step S15, a second preferred point 32 and a third preferred point 33 are defined on two edges 111, 112 adjacent to the first control region 11. Furthermore, and the first axial streets 21 pass through the edges 111 and the second axial streets 22 pass through the edges 112.
In step S16, step S15 is repeated to determine a second control region 12 adjacent to the first control region 11 based on the second preferred point 32, and the first axial streets 21 are included in the first control region 11 and the second control region 12.
In step S17, step S16 is repeated to determine a third control region 13 adjacent to the first control region 11 based on the third preferred point 33, and the second axial streets 22 are included in the first control region 11 and the third control region 13, such that the three control regions 11, 12, 13 form a web.
In this embodiment, in step S17 and step S16, the first and second axial average vehicle speeds V1, V2 are 60 km/hr and the first and second axial preferred allowed travel time periods t1, t2 are 60 seconds, the first vehicle travel distance L1 and the second travel distance L2 of the second control region 12 and the third control region 13 will be 1 km, such that all three control regions 11, 12, 13 have the same size.
In this embodiment, step S15, step S16, and step S17 are repeated to determine a fourth, fifth, sixth, seventh, eighth, and ninth control region 14, 15, 16, 17, 18, 19. The control regions 11, 12, 13, 14, 15, 16, 17, 18, 19 are arranged as a web, such that the first axial streets 21 and the second axial streets 22 pass through every control region 11, 12, 13, 14, 15, 16, 17, 18, 19, and every control region 11, 12, 13, 14, 15, 16, 17, 18, 19 has a plurality of traffic lights 7 (as shown in
In step S18, the plurality of traffic lights 7 in the first control region 11 are controlled to display green lights to the vehicles traveling on the first axial streets 21 and red lights to the vehicles traveling on the second axial streets 22 according to the first axial preferred allowed travel time period t1 (as shown in
Furthermore, the plurality of traffic lights 7 in the second control region 12 and the third control region 13 are controlled to display red lights to the vehicles traveling on the first axial streets 21 and green lights to the vehicles traveling on the second axial streets 22 according to the second axial preferred allowed travel time period t2. As shown in
In this embodiment, all traffic lights in the fourth, fifth, sixth and ninth control regions 14, 15, 16, 19 are respectively controlled to display green lights to the vehicles traveling on the first axial streets 21 according to the first axial preferred allowed travel time period t1 and to display red lights to the vehicles traveling on the second axial streets 22; and all traffic lights in the seventh and eighth control regions 17, 18 are respectively controlled to display red lights to the vehicles traveling on the first axial streets 21 according to the second axial preferred allowed travel time period t2 and to display green lights to the vehicles traveling on the second axial streets 22.
In step S19, the traffic lights on the control regions 11, 12, 13 on the same axial streets 21, 21 are linked by serializing the preferred allowed travel time periods t1, t2 to display either green lights or red lights in alternation in the control regions 11, 12, 13 together. For example, all traffic lights in the first control region 11 display red lights to the vehicles traveling on the first axial streets 21 and green lights to the vehicles traveling on the second axial streets 22 from 1 min 0th second to 1 min 59th second; meanwhile all traffic lights 7 in the second and third control region 12, 13 display green lights to the vehicles traveling on the first axial streets 21 from 1 min 0th second to 1 min 59th second and red lights to the vehicles traveling on the second axial streets 22 from 1 min 0th second to 1 min 59th second. In this embodiment, the traffic lights 7 in the control region 14, 15, 16, 17, 18, 19 on the control regions 11, 12, 13 on the same axial streets 21, 22 are linked by serializing the preferred allowed travel time periods t1, t2 to display either green lights or red lights in an alternating manner in the control regions 11, 12, 13 together.
In addition, the preferred allowed travel time periods t1, t2 include displaying a green light and a yellow light in sequence.
Please refer to
The reasons for the vehicles 41, 42 needing to stop at red lights will be: speeding, driving too slow, car accidents, traffic jams, etc.
Please refer to
During the 0th sec to the 59th sec (as shown in
In order to smooth traffic conditions, the present invention can also utilize the following conditions: the axial streets 21, 21b, 22, 22b can be two-way streets and employ no-left-turn signs.
The axial streets 21b, 22b and a plurality of sub-streets 23b, 24b (as shown in
A vehicle maximum speed limit Vmax may be defined based on the vehicle average travel speed and the following formula:
V
max=(1+A %)·V (1)
wherein A % is a predetermined vehicle speed increasing ratio, which is defined according to the road conditions; and V is the vehicle average travel speed.
Therefore, the first axial vehicle average travel speed V1 (wherein V1=V) is used to obtained the first axial vehicle average travel speed limit Vmax as follows:
V
max=(1+A %)·V1 (2)
When the second axial vehicle average travel speed V2 (wherein V2=V) may be used to obtain the second axial vehicle average travel speed limit Vmax as follows:
V
max=(1+A %)·V2 (3)
Wherein, A can be selected from a range 10 to 20, which is used for accommodating different unpredictable factors such as starting time, speeding, slow driving speeds, accidents on road, going through turns, etc.
Please refer to
At the 0th second, two vehicles 41c, 45c respectively move along the first axial streets 21c in the control region A 61c and the control region C 63c; two vehicles 43c, 44c respectively move along the first axial streets 21c in the control region B 62c, and a vehicle 42c moves along the first axial streets 21c in the control region A 61c and the control region B 62c. All of the vehicles 41c, 42c, 43c, 44c, 45c move with the first axial vehicle average travel speed V1.
During the 0th sec to the 59th sec, all traffic lights in the first axial streets 21c in the control region A 61c and the control region C 63c, display red lights such that the vehicles 41c, 45c need to stop for a green light; and all traffic lights in the first axial streets 21c in the control region B 62c display green lights such that the vehicles 43c, 44c move into the control region C 63c and stop behind the vehicle 45c. The vehicle 42c moves through the control region B 62c and stops behind the vehicle 43c.
During the 1 min 0th sec to the 1 min 59th sec, all traffic lights in the first axial streets 21c in the control region A 61c and the control region C 63c display green lights such that the vehicles 42c, 43c, 44c, 45c move through the control region C 63c and the vehicle 41c moves through the control region A 61c. During the 2 min 0th sec to the 2 min 59th sec, all traffic lights in the first axial streets 21c in the control region B 62c and the control region D 64c, display green lights such that the vehicles 42c, 43c, 44c, 45c move through the control region D64c and the vehicle 41c moves through the control region B 62c.
During the 3 min 0th sec to the 3 min 59th sec, all traffic lights in the first axial streets 21c in the control region D 64c display red lights, but the vehicles 42c, 43c, 44c, 45c have already left the last intersection 201c; and all traffic lights in the first axial streets 21c in the control region C 63c display green lights such that vehicle 41c moves through the control region C 63c. Therefore, after several occurrences of light changes, the vehicles in the area naturally form into groups and move with the respective average speed.
Please refer to
Please refer to
The control method can also be applied to a highway, and the axial vehicle average speeds V1, V2 and the preferred allowed travel time periods t1, t2 can be adjusted based on the traffic condition on the highway and related highways.
Therefore, the control method of the present invention is suitable for several control regions and may be used for synchronously controlling traffic lights for the control regions. Therefore, the vehicles in the control regions need only move with the axial vehicle average speeds V1, V2, to enter into the next control region and the next one, etc. Accordingly, the control method can reduce vehicle travel times, air pollution, noise pollution, and wasted fuel.
Please refer to
Although the present invention has been explained in relation to its preferred embodiment, it is to be understood that many other possible modifications and variations can be made without departing from the spirit and scope of the invention as hereinafter claimed.
Number | Date | Country | Kind |
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098136268 | Oct 2009 | TW | national |