The present invention relates to a method for increasing vehicle flow through an intersection.
Traffic lights and intersections are ubiquitously used to regulate traffic coming from perpendicular directions in order to avoid collisions. While intersections are advantageous for collision avoidance, they are also responsible for the sub-optimal usage of existing roads leading to traffic congestion. For example, when a traffic signal turns from green to red, vehicles come to a stop at the traffic light and subsequent vehicles pile up in the stretch of road leading up to the intersection. While these vehicles are waiting for the traffic signal to turn green again, the stretch of road immediately after the intersection is often empty and therefore, underutilized. If a given traffic signal is green 50% of the time and red 50% of the time, this means that the existing road immediately following the intersection is only being used 50% of the time. Furthermore, when one takes into account the amount of time needed for a car that is stopped at a red light to accelerate to a normal speed, the actual rate at which the aforementioned stretch of road is being used is less than 50%. One can imagine that on a road with multiple intersections, this situation becomes exponentially more problematic, leading to exacerbated traffic congestion. One solution that has been employed to combat the congestion caused by intersections is the construction of overpasses that bypass these sections of the road. Though effective, overpasses are time-consuming and expensive to construct and maintain. In addition, especially in cities, it is often impossible to vacate the considerable amount of space required for construction of overpasses, a process which may lead to further unwanted traffic congestion.
The purpose of this invention is to use a simple, efficient and cost-effective method to increase the effectiveness of intersections leading to significantly increased traffic flow rates. Traffic congestion, particularly that seen in densely populated cities, will as a result see tremendous improvement.
A method for increasing the rate of traffic flow through an intersection according to the present invention will be described hereinafter.
With reference to the drawings, without loss of generality, the arrows (7) indicate a direction of the vehicle flow, that is, a south to north route. The method for increasing the traffic flow through an intersection comprises: additional lanes are designated in a stretch of road (2) immediately preceding a traffic light (1) in the intersection; and the same quantity of additional lanes are designated in a stretch of road (3) immediately following the traffic light. When the traffic light turns red, all vehicles come to a stop. When the traffic light turns green, the vehicles traverse the intersection and enter into the stretch of road immediately following the traffic light (3). During this time, vehicles positioned in the priority lanes (6) continue to move forward, while vehicles positioned in the non-priority lanes (4) come to a stop or slow down until the traffic light turns from green to red. When all vehicles in the priority lanes (6) have emptied from the stretch of road immediately following the traffic light, vehicles from the non-priority lanes are now allowed to move on their route. If the stretch of road following the traffic light is sufficiently lengthy, vehicles from the non-priority lanes may merge safely in with those in the priority lanes and do not need to come to a complete stop.
Installation of signs and/or traffic lights as clear regulatory signals for drivers will ensure safety and efficiency. Procedures governing the use of the stretch of road immediately following the intersection (3) can be modified as needed.
In addition to the vehicle stop lines present in existing lanes in an intersection (5), a number (N) of additional vehicle stop lines (5) will be designated. When a traffic light turns red, each car should line up single-file at equidistant intervals according to the vehicle stop lines. The purpose of this is to allow vehicles to accelerate at a similar pace. This is an improvement over the current situation where the distance between vehicles stopped when the traffic light turns red is so minimal that it requires vehicles to wait until all vehicles before them have left before they are able to accelerate and move on. For example, currently, the 11th car must wait for the previous 10 vehicles to accelerate and leave before moving on. Assuming it takes about 2 seconds (in reality this is likely an underestimation) for each car to start moving, the 11th car must wait 20 seconds before it can begin accelerating. Using the method in this proposal, there is no need for the waiting period. If a traffic light is green for about 1 to 2 minutes on average, the time the 11th car spends idling under current conditions (20 seconds) is approximately 33% and 16% respectively—a significant amount of time.
In terms of increasing traffic flow, the number (N) of additional vehicle stop lines should be determined such that the nth vehicle can safely depart the non-priority lane prior to the traffic light turning green again.
The use of this method would require additional stretches of space to accommodate the non-priority lanes. However, the amount of space would not exceed that of normal traffic flow, when vehicle are running, and therefore, should not be of concern.
Compared with the existing method in the prior art, the method of the present invention has the following advantageous aspects.
Wherein:
An embodiment of the method for increasing traffic flow will be described in detail hereinafter.
With reference to
Number | Date | Country | Kind |
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200710194589.3 | Dec 2007 | CN | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/CN2008/001927 | 11/26/2008 | WO | 00 | 8/20/2010 |