Patent Publication Number: US-5897270-A

Title: Vehicle highway system having single-level uninterrupted traffic-flow intersection

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a vehicle highway system, and particularly to one having single-level intersections capable of uninterrupted traffic flow. 
     2. Description of Related Art 
     Highway systems which include intersections of a major road with secondary roads generally include either a stop sign or a traffic signal light in order to permit the traffic on the secondary road to cross the main road. If the traffic on the main road is relatively heavy, the danger of an accident occurring when a vehicle on the secondary road attempts to cross the main road generally requires that a traffic control signal be provided at the intersection, but such a signal seriously interrupts the continuous flow of the traffic on the main road. In many cases, this problem is answered by building overpasses or underpasses to permit the traffic on the secondary roads to cross the main road without interrupting the main road traffic, but such overpass and underpass constructions are relatively expensive. 
     SUMMARY OF THE INVENTION 
     An object of the present invention is to provide a highway system having single-level intersections capable of uninterrupted traffic flow. 
     According to the present invention, there is provided a highway system for vehicular traffic including an intersection of a major road and a secondary road each having traffic sections of opposite directions separated by a center line; the major road including: a first barrier along its center line preventing traffic on the secondary road from directly crossing the main road; a bypass stretch for each direction section of the main road and at a predetermined distance forwardly of the intersection in the traffic direction on the respective section, each bypass stretch having an entrance end, an exit end, and a lane-dividing line at the exit end; a second barrier for each direction section of the main road directing all the traffic in the respective section into the entrance end of the respective bypass stretch; and a third barrier for each direction section of the main road forwardly of the second barrier in the traffic direction to define a return stretch of the main road between the second and third barriers bypassed by the bypass stretch; the third barrier extending from the lane-dividing line at the exit end of the respective bypass stretch to the center line of the main road to thereby direct the traffic exiting the bypass stretch on one side of its lane-dividing line in the reverse direction onto the reverse stretch of the main road, and the traffic exiting the bypass stretch on the opposite side of its lane-dividing line in the forward direction onto the main road; the return stretch of the main road being devoid of a barrier along its center line to permit the traffic thereon to merge with the traffic on the main road travelling in the opposite direction. 
     As will be described more particularly below, such a highway system permits the traffic on the secondary roads to enter or cross the main road without interrupting the traffic on either road, and without the need for overpasses or underpasses with respect to the main road. 
    
    
     BRIEF DESCRIPTION OF THE DRAWING 
     Further features of the invention will be apparent from the description below of one form of highway system constructed in accordance with the present invention as illustrated in the attached single drawing figure which shows a main road intersected by a plurality of secondary roads. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The highway system illustrated in the attached drawing includes a main road MR intersected by a plurality of secondary roads SR 1  -SR n  along the length of the main road. The main road MR includes a center line MCL dividing the road into traffic section MTSa having one or more lanes for carrying the traffic in one direction, and traffic section MTSb having one or more lanes for carrying the traffic in the opposite direction. Similarly, each of the secondary road SR 1  -SR n  also includes a center line (e.g., SCL road for secondary road SR 1 ) dividing the road into a traffic section STSa for carrying the traffic in one direction, and a traffic section STSb for carrying the traffic in the opposite direction. 
     In the example illustrated in the drawing, the main road is a four-lane road including two lanes for each direction, and the secondary roads SR 1  -SR n  are two-lane roads including a single lane for each direction. It will be appreciated, however, that such an arrangement is illustrated merely for purposes of example, and that the invention is capable of application in many other types of highway constructions. 
     The main road MR is provided with a traffic barrier TB 1  extending along its center line at each of the intersections with the secondary road SR 1  -SR n  preventing traffic on the respective secondary road from directly crossing the main road. In the example illustrated in the drawing, traffic barrier TB 1  is common for the intersections of all the secondary roads SR 1  -SR n  illustrated in the drawing, but it will be appreciated that there could be a separate barrier at each intersection particularly if the intersections are spaced substantial distances apart. 
     The main road MR further includes a bypass stretch for each direction section of the main road and at a predetermined distance forwardly of the intersection in the traffic direction of the respective section. Thus, as shown in FIG. 1, a bypass stretch BSa is provided for the traffic carried by traffic section MTSa of the main road MR forwardly of the all the illustrated secondary roads SR 1  -SR n  in the direction of the traffic flow; similarly, a bypass stretch BSb is provided for the opposite traffic section MTSb of the main road MR forwardly of all the illustrated intersections with the secondary roads SR 1  -SR n  in the direction of traffic flow. 
     Each of the bypass stretches BSa, BSb includes an entrance end for receiving the traffic from the respective section of the main road, and an exit end for returning the traffic to the respective section of the main road. In addition, each of the bypass stretches BSa, BSb, at least their exit ends, includes a lane-dividing or center line BCLa, BCLb, defining at least two lanes of traffic exiting from the respective bypass stretch. 
     The main road MR further includes a second traffic barrier TB 2a , TB 2b , for each direction section of the main road. These traffic barriers are connected to the center line MCL of the main road so that they direct all the traffic in the respective section of the main road into the entrance end of the respective bypass stretches BSa, BSb. 
     The main road MR includes a third traffic barrier TB 3a , TB 3b  for each direction section of the main road at the exit end of each bypass stretch BSa, BSb, i.e., fowardly of the second traffic barriers TB 2a , TB 2b  in the traffic direction. These third traffic barriers TB 3a , TB 3b , extend from the lane-dividing or center line at the exit end of the respective bypass section BSa, BSb to the center line MCL of the main road MR. Barriers TB 3a , TB 3b  are therefore effective to direct the traffic exiting from the right side of the center line at the exit of the respective bypass stretch BSa, BSb, onto the main road MR in the direction of traffic travel in the respective section, so that the forwardly-travelling traffic continues in the same direction. These barriers, however, direct the traffic exiting from the respective bypass stretches BSa, BSb on the left side of the center line at the exit of the respective bypass stretch in the reverse direction onto a return stretch RSa, RSb of the main road MR extending between the two barriers TB 2a , TB 3a  and TB 2b , TB 3b  bypassed by the respective bypass stretch BSa, BSb. 
     It will thus be seen that the traffic in each of the bypass stretches RSa, RSb, travels in the reverse direction to the traffic in the corresponding sections of the main road MR. As shown in the drawing, these reverse stretches are RSa, RSb of the main road are devoid of a barrier along the center line MCL of the main road. These reverse stretches therefore permit the traffic thereon to merge with the traffic travelling in their respective directions in the opposite sections of the main road, as shown by the arrows in the reverse stretches RSa, RSb. The traffic which is to continue in the same direction would remain in the left side of the respective section of the main road MR, whereas the traffic to exit from the main road MR via one of the secondary roads SR 1  -SR n , would edge to the right of the respective section of the main road MR to enable it to leave at the desired secondary road. 
     Thus, if the traffic on the secondary road SR 1  was merely to cross the main road MR, such traffic in the reverse stretch RSa, RSb would leave the main road via the secondary road SR 1 , thereby in effect crossing the main road without any interruption in the traffic flow. 
     Since the traffic travelling on the main road MR on opposite sides of the second traffic barrier TB 2a , TB 2b  is travelling in opposite directions, barriers TB 2a , TB 2b  should also be optical barriers, i.e., also blocking the view of the traffic approaching the opposite sides of the barrier. 
     It will thus be seen that the system illustrated in the drawing permits the traffic to flow from any of the secondary roads SR 1  -SR n  across the main road MR or onto the main road without any interruption in the traffic flow along either the main road MR or any of the secondary roads SR 1  -SR n . It will also be seen that such an arrangement does not require overpasses or underspasses, and therefore all the intersections may be construction in the same level. 
     While the invention has been described with respect to one preferred embodiment, it will be appreciated that this is set forth merely for purposes of example, and that many other variations, modifications and applications of the invention may be made.