Abstract:
The present invention relates to road traffic field, providing a two-level continuous flow crossroad and construction method and prefabricated parts thereof. The crossroad comprises a first road and a second road intersected with each other. At least one overpass or underpass crosses the first road and merges with the second road. The overpass or underpass each has a bypass branched from one side thereof. The bypass merges with the first road. The construction method includes constructing the two roads or starting from two existing roads. The prefabricated parts include a vaulted strip main body for overpass and vaulted strip for U-turn. Upon the crossroad of the present invention, traffics can make left turn, right turn and U-turn and go ahead without interruption. The crossroad of the present invention has simple structure and takes up less land.

Description:
CROSS REFERENCES TO RELATED APPLICATIONS  
       [0001]     This application is related to and claims priority to Chinese Application No. 200510033805.7, filed Mar. 22, 2005, incorporated herein by reference in its entirely.  
       BACKGROUND OF THE PRESENT INVENTION  
       [0002]     1. Field of Invention  
         [0003]     The present invention relates to a crossroad, and more particularly to a two-level continuous flow crossroad and construction method and prefabricated parts thereof.  
         [0004]     2. Description of Related Arts  
         [0005]     Traffic jam at intersection of roads is a conventional problem all over the world. Multi-level roadway interchanges, which permit continuous traffic flow, are commonly used, but they take up much land, time and money to build and are impractical in a crowded city environment. Major crossroads controlled by traffic lights are also widely employed, but vehicles are required to stop on the red light, and are free to go on the green light. These types of mono-level interchange cannot effectively handle large volume in major cities. In addition, traffic accidents occur frequently at crossroads.  
         [0006]     U.S. Pat. No. 4,955,751 issued to Tsai et al on Sep. 11, 1990, provide a crossroad without traffic light, where vehicles can run without interruption. But only one way is provided for vehicles to go straight or make left turn, right turn and U-turn.  
       SUMMARY OF THE PRESENT INVENTION  
       [0007]     A primary object of the present invention is to provide a crossroad without disadvantage mentioned above which permit continuous traffic flow.  
         [0008]     Another object of the present invention is to provide a crossroad where vehicles can either drive straight through or turn without interruption.  
         [0009]     Another object of the present invention is to provide a crossroad where vehicles can make turns in several ways.  
         [0010]     Another object of the present invention is to provide a construction method of a crossroad.  
         [0011]     Another object of the present invention is to provide prefabricated parts for constructing a crossroad.  
         [0012]     Accordingly, in order to accomplish the above objects, on one aspect, the present invention provides a crossroad comprising: 
        a first road;     a second road intersected with said first road; and     at least one overpass or underpass crossing said first road;     wherein said overpass or underpass each has a entrance at one end and a exit at the other end where said overpass or underpass merges with said second road, said overpass or underpass each has a bypass branched from one side thereof, said bypass merges with said first road.        
 
         [0017]     On another aspect, the present invention provides a construction method of a crossroad, including: 
        constructing a first road and a second road intersected from each other or starting from existing two roads intersected from each other;     constructing at least one overpass or underpass crossing said first road and merging with said second road;     wherein said overpass or underpass each has a entrance at one end and a exit at the other end where said overpass or underpass merges with said second road, said overpass or underpass each has a bypass branched from one side thereof, said bypass merges with said first road.        
 
         [0021]     On another aspect, the invention provides a prefabricated part for constructing a crossroad, comprising a vaulted strip main body for overpass, wherein said vaulted strip main body has a branch for bypass.  
         [0022]     On another aspect, the invention provides a prefabricated part for constructing a crossroad, comprising a vaulted strip, wherein said vaulted strip is installed on said first road and over said entrance for U-turn.  
         [0023]     Further objectives and advantages of the present invention will become apparent from the detailed description provided hereinbelow. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the present invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the present invention will become apparent to those skilled in the art from this detailed description.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0024]      FIG. 1  is a schematic top elevational view of a crossroad according to a first embodiment of the present invention, illustrating vehicles traveling on the right side of roads, wherein overpasses is provided;  
         [0025]      FIG. 2  is a schematic top elevational view of a crossroad according to an alternative embodiment of the present invention, illustrating vehicles traveling on the left side of roads, wherein overpasses is provided;  
         [0026]      FIG. 3  is a schematic top elevational view of a crossroad according to another alternative embodiment of the present invention, illustrating vehicles traveling on the right side of roads, wherein overpasses is provided;  
         [0027]      FIG. 4  is a schematic top elevational view of a crossroad according to another alternative embodiment of the present invention, illustrating vehicles traveling on the right side of roads, wherein overpasses is provided;  
         [0028]      FIG. 5  is a schematic top elevational view of a prefabricated part for overpass according to the present invention, illustrating vehicles traveling on the right side of roads, wherein bypass is U-shaped;  
         [0029]      FIG. 6  is a schematic top elevational view of a prefabricated part for overpass according to the present invention, illustrating vehicles traveling on the right side of roads, wherein bypass is a strip;  
         [0030]      FIG. 7  is a schematic top elevational view of a prefabricated part for overpass according to the present invention, illustrating vehicles traveling on the right side of roads, wherein the prefabricated part is installed over an entrance for U-turn.  
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0031]     Referring to  FIG. 1  and  FIG. 2 , a crossroad comprises road  1  and road  2  intersected from each other. The road  1  has two roadway  11  and roadway  13  separated by a median  12 . The roadway  11  is for traffic traveling in one direction. The roadway  13  is for traffic traveling in one direction opposition to that of the roadway  11 . The road  2  has roadway  21  and roadway  23  separated by a median  22 . The roadway  21  is for traffic traveling in one direction. The roadway  23  is for traffic traveling in one direction opposition to that of the roadway  21 . Two entrances for U-turn  121  and  122  are provided between the roadway  11  and the roadway  13  and on opposite side of the road  2  respectively. Two entrances for U-turn  221  and  223  are provided between the roadway  21  and the roadway  23  and on opposite side of the road  1  respectively. Two entrances for turn  222  and  224  are provided between the roadway  21  and the roadway  23  and on opposite side of the road  1  respectively.  
         [0032]     Referring to  FIG. 1 , which illustrates vehicles traveling on the right side of the road. Two overpasses  24  and  25  cross the road  1  and merge with the roadway  21  and the roadway  23  respectively. Two ends of the overpass  24  are connected to the road surface of the roadway  21 . Two ends of the overpass  25  are connected to the road surface of the roadway  23 . The overpass  24  has an entrance  242  at one end and an exit  243  at the other end. The overpass  25  has an entrance  252  at one end and an exit  253  at the other end. The exit  253  is spaced farther from the road  1  than the entrance  242  on the same side of the road  1 . A distance between the exit  253  and the entrance  242  is set so that a vehicle from the entrance for turn  222  can smoothly drive into the entrance  242 . The exit  243  is spaced farther from the road  1  than the entrance  252  on the same side of the road  1 . A distance between the exit  243  and the entrance  252  is set so that a vehicle from the entrance for turn  224  can smoothly drive into the entrance  242 .  
         [0033]     A bypass  241  is branched from one side of the overpass  24 . An end  2411  of the bypass  241  connected to inside road surface of the roadway  13 . The bypass  241  is defined by two arms and U-shaped. And the two arms are not in a same plane. The arm connected to the overpass  24  is longer than the arm connected to the roadway  13 . An intermediate section of the two arms is wider the two arms. A bypass  251  is branched from one side of the overpass  25 . An end  2511  of the bypass  251  connected to inside road surface of the roadway  11 . The bypass  251  is similar to the bypass  241  in shape.  
         [0034]     The entrance for U-turn  221  is spaced farther from the road  1  than the entrance  242  on the same side of the road  1 . A distance between the entrance for U-turn  221  and the entrance  242  is set so that a vehicle from the entrance for U-turn  221  can smoothly drive into the entrance  242 . The entrance for U-turn  223  is spaced farther from the road  1  than the entrance  252  on the same side of the road  1 . A distance between the entrance for U-turn  223  and the entrance  252  is set so that a vehicle from the entrance for U-turn  223  can smoothly drive into the entrance  252 .  
         [0035]     The entrance for turn  222  is spaced between the entrance for U-turn  221  and the entrance  242 . A distance between the entrance for turn  222  and the entrance  242  is set so that a vehicle from the entrance for turn  222  can smoothly drive into the entrance  242 . The entrance for turn  224  is spaced between the entrance for U-turn  223  and the entrance  252 . A distance between the entrance for turn  224  and the entrance  252  is set so that a vehicle from the entrance for turn  224  can smoothly drive into the entrance  252 .  
         [0036]     An overpass  14  crosses the entrance for U-turn  121  and merges the roadway  13 . Both two ends of the overpass  14  are connected to inside road surface of the roadway  13 . An overpass  15  crosses the entrance for U-turn  122  and merges the roadway  11 . Both two ends of the overpass  15  are connected to inside road surface of the roadway  11 .  
         [0037]     A vehicle A and a vehicle D can drive straight through the crossroad without interruption on the roadway  21  and the roadway  11  respectively.  
         [0038]     To turn right, the vehicle A follows the arrow a; the vehicle D follows the arrow d. Alternatively, the vehicle A goes across the overpass  24 , the entrance for U-turn  223  and the entrance  252  so as to enter the bypass  251  and merge into the roadway  11 ; the vehicle D goes across the entrance for U-turn  12 , then follows the arrow c, then goes across the entrance for turn  224  so as to merges into the roadway  23 . Also, the vehicle A can goes across the overpass  24  and the entrance for U-turn  223 , and then follows the arrow b and goes across the entrance for U-turn  121  and merges into the roadway  11 .  
         [0039]     To turn left, the vehicle A enter the entrance  242  so as to enter the bypass  241  and merges into the roadway  13 ; the vehicle D follows the arrow d and goes across the entrance for turn  222  so as to merges into the roadway  12 . Alternatively, the vehicle A follows the arrow a and goes across the entrance for U-turn  122  so as to merges into the roadway  13 ; the vehicle D goes across the entrance for U-turn  122 , then follows the arrow c so as to merge into the roadway  21 . Also, the vehicle A can goes across the overpass  24  and the entrance for U-turn  223 , and then follows the arrow b so as to merge into the roadway  13 .  
         [0040]     To do a U-turn, the vehicle A goes across the entrance for U-turn  223  so as to merge into the roadway  23 ; the vehicle D goes across the entrance for U-turn  122  so as to merge into the roadway  13 . Alternatively, the vehicle A follows the arrow a and goes across the entrance for U-turn  122  and the entrance for U-turn  121  in turn, and then follows the arrow d so as to merge into the roadway  23 ; the vehicle D follows the arrow d, and then enter the entrance  242  and the bypass  241  so as to merge into the roadway  13 .  
         [0041]     Other ways for the vehicle A and D to make right or left turn and U-turn is not illustrated. The movements of the vehicle B and C are respectively similar to that of the vehicle A and D.  
         [0042]     Not illustrated in drawings, all the overpasses in  FIG. 2  can be replaced by underpasses. In the case of underpasses, the structure of the crossroad is similar to that of the crossroad recited above. The movements of vehicles are also similar.  
         [0043]     Referring to  FIG. 2 , which illustrates vehicles traveling on the left side of roads. The structure of the crossroad is similar to that of the crossroad in FIG  2 . The overpasses  24  and  25  accommodate vehicles to travel on the left side of roads. The movements of vehicles are also similar but on the left side of roads.  
         [0044]     Not illustrated in drawings, all the overpasses in  FIG. 2  can be replaced by underpasses. In the case of underpasses, the structure of the crossroad is similar to that of the crossroad recited above. The movements of vehicles are also similar.  
         [0045]     Referring to  FIG. 3 , a crossroad comprises road  1  and road  2  intersected from each other. The road  1  has one roadway for traffic traveling in one direction. The road  2  has roadway  21  and roadway  23  separated by a median  22 . The roadway  21  is for traffic traveling in one direction. The roadway  23  is for traffic traveling in one direction opposition to that of the roadway  21 .  
         [0046]     An overpass  24  crosses the road  1  and merges with the roadway  21 . Two ends of the overpass  24  are connected to the road surface of the roadway  21 . The overpass  24  has an entrance  242  at one end and an exit  243  at the other end.  
         [0047]     A bypass  241  is branched from the overpass  24 . The bypass  241  is a strip. An end  2411  of the bypass  241  connected to the road surface of the road  1 .  
         [0048]     An overpass  25  crosses the road  1  and merges with the roadway  23 . Two ends of the overpass  25  are connected to the road surface of the roadway  23 . The overpass  25  has an entrance  252  at one end and an exit  253  at the other end.  
         [0049]     A bypass  251  is branched from the overpass  25 . An end  2411  of the bypass  241  connected to the road surface of the road  1 . The bypass  241  is defined by two arms and U-shaped. And the two arms are not in a same plane. The arm connected to the overpass  25  is longer than the arm connected to the roadway  13 . An intermediate section of the two arms is wider the two arms.  
         [0050]     Two entrances for U-turn  221  and  222  are provided between the roadway  21  and the roadway  23  and on opposite side of the road  1  respectively. The entrance for U-turn  221  is spaced farther from the road  1  than the exit  253  so that a vehicle from the exit  253  can smoothly make a U-turn. The Entrance for U-turn  222  is spaced farther from the road  1  than the exit  243  so that a vehicle from the exit  243  can smoothly make a U-turn.  
         [0051]     A vehicle A goes straight across the overpass  24 . To turn right, the vehicle A follows the arrow a. Alternatively, the vehicle A enters the entrance  242  and the bypass  241  so as to merge into the road  1 .  
         [0052]     A vehicle B goes straight across the overpass  25 . To turn left, the vehicle B enters the entrance  252  and the bypass  251  so as to merge into the road  1 . Alternatively, the vehicle B goes across the overpass  25  and the entrance for U-turn  221 , and then does the same movement of the vehicle A in turning right.  
         [0053]     A vehicle C goes straight smoothly. To turn right, the vehicle C follows the arrow c 1 . To turn left, the vehicle C follows the arrow C 2 .  
         [0054]     Not illustrated in drawings, all the overpasses in  FIG. 3  can be replaced by underpasses. In the case of underpasses, the structure of the crossroad is similar to that of the crossroad recited above. The movements of vehicles are also similar.  
         [0055]     Not illustrated in drawings, the crossroad illustrating in  FIG. 3  can be changed to accommodate vehicles to travel in the left side of roads.  
         [0056]     Referring to  FIG. 4 , a crossroad comprises road  1  and road  2  intersected from each other. The road  1  and  2  each has one roadway for traffic traveling in one direction.  
         [0057]     An overpass  21  crosses the road  1  and merges with the road  2 . Two ends of the overpass  21  are connected to the road surface of the road  2 .  
         [0058]     A bypass  211  is branched from the overpass  21 . The bypass  241  is a strip. The bypass  241  has an entrance  2411  connected to the road surface of the road  1 .  
         [0059]     A vehicle A goes straight across the overpass  21 . To turn right, the vehicle A follows the arrow a.  
         [0060]     A vehicle B goes straight smoothly. To turn left, the vehicle B enters the entrance  252  and the bypass  251  so as to merge into the road  2 .  
         [0061]     Not illustrated in drawings, all the overpasses in  FIG. 4  can be replaced by underpasses. In the case of underpasses, the structure of the crossroad is similar to that of the crossroad recited above. The movements of vehicles are also similar.  
         [0062]     Not illustrated in drawings, the crossroad illustrating in  FIG. 4  can be changed to accommodate vehicles to travel in the left side of roads.  
         [0063]     Referring to  FIG. 1  to  FIG. 4 , a construction method of a crossroad includes constructing two roads intersected from each other and at least one overpass or underpass with a bypass. The construction method can start form two existing roads intersected from each other. Alternatively, the overpass is prefabricated and installed on one of the two roads.  
         [0064]     Referring to  FIG. 5 , illustrating a prefabricated part for constructing a crossroad, the prefabricated part comprises a vaulted strip main body for overpass. The vaulted strip main body has a branch for bypass. The branch is defined by two arms and U-shaped. And the two arms are not in a same plane. The arm connected to the vaulted strip main body is longer than the arm connected to a roadway. An intermediate section of the two arms is wider the two arms.  
         [0065]     Referring to  FIG. 6 , illustrating a prefabricated part for constructing a crossroad, the prefabricated part comprises a vaulted strip main body for overpass. The vaulted strip main body has a branch for bypass. The branch is a strip, which has a wider end connected to the vaulted strip main body.  
         [0066]     Referring to  FIG. 7 , illustrating a prefabricated part for constructing a crossroad, the prefabricated part comprises a vaulted strip for installing over an entrance for U-turn.  
         [0067]     According to different requirements, the prefabricated parts vary in length, width and thickness. Material for making the prefabricated parts can be chosen from steel, steel and concrete and the like.  
         [0068]     According to different traffic condition, each roadway of the road the crossroad has one or more lanes.  
         [0069]     As described with numerous exemplary embodiments, a two-level continuous flow crossroad and construction method and prefabricated parts thereof are proposed. However, for those skilled in this field, these exemplary embodiments can be easily adapted and modified to suit additional applications without departing from the spirit and scope of this invention. For example, with minor modification, two-level continuous flow crossroad and construction method and prefabricated parts thereof are applicable to the intersection of crossroads shaped          ,          , and          . Thus it is to be understood that the present disclosure has been made by way of example only and that numerous changes in the detailed construction and the combination and arrangement of parts may be resorted to without departing from the spirit and scope of the invention as hereinafter claimed.