US20100303544A1

US20100303544A1 - Method for increasing vehicle flow through an intersection

Info

Publication number: US20100303544A1
Application number: US12/746,144
Authority: US
Inventors: Yongnan Xuan
Original assignee: Individual
Current assignee: Individual
Priority date: 2007-12-03
Filing date: 2008-11-26
Publication date: 2010-12-02
Also published as: WO2009074009A1; CN101350133A

Abstract

This method increases the number of lanes immediately preceding and immediately following a given intersection. When the traffic signal is red, vehicles must come to a stop. When the traffic signal turns green, vehicles traverse the intersection and enter the stretch of road immediately following the intersection (3). Of these, vehicles in the priority lanes (6) move on while those in the non-priority lanes must slow and/or stop. When the traffic light turns red and all vehicles from the priority lanes have safely left the area, vehicles in the non-priority lanes can safely merge back into the priority lanes and move on. This method results in a tremendous increase in the traffic flow rate in intersections.

Description

FIELD OF THE INVENTION

The present invention relates to a method for increasing vehicle flow through an intersection.

BACKGROUND OF THE INVENTION

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.

SUMMARY OF THE INVENTION

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 11^thcar 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 11^thcar 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 11^thcar 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.

- A. When a traffic light turns red, the stretch of road immediately following the light is still being utilized. This leads to a dramatic increase in traffic flow thereby increasing the efficiency of the intersection and tremendously improving traffic conditions.
- B. Because of the simplicity of the method, it is a superior alternative to the current solution of constructing expensive, time-consuming construction of overpass structures.
- C. Due to increased traffic flow, vehicles spend less time idling, which results in lower polluting emissions being released into the environment.
- D. The designation of additional lanes allows more vehicles to traverse an intersection in a given amount of time with minimal changes to the existing road infrastructure.
- E. Signs denoting optimal speed limits as vehicles approach the intersection reduce the time spent idling at a red light.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of the method according to an embodiment of the present invention.

Wherein:

- 1 The traffic light at a given intersection;
- 2 The stretch of road preceding the traffic light (where additional lanes are designated);
- 3 The stretch of road immediately following the traffic light (where additional lanes are designated);
- 4 Existing lanes;
- 5 Vehicle stop lines (multiple)
- 6 Priority lanes;
- 7 The direction of traffic flow.

DESCRIPTION OF THE PREFERRED EMBODIMENT

An embodiment of the method for increasing traffic flow will be described in detail hereinafter.
With reference to FIG. 1, the method relates to an intersection of two-lane roads. In the stretch of road preceding the traffic light in the intersection 2, the existing lanes 4 are expanded to include two additional lanes; the same applies to the stretch of road immediately following the traffic light in the intersection 3. When the traffic light turns green, vehicles waiting in all lanes traverse the intersection and enter the section immediately following 3. Of those, the vehicles in the priority lanes 6 will move on, while those in the non-priority lanes slow down or stop until the traffic light turns red and the priority lanes 6 are empty, then vehicles in the non-priority lanes safely merge into the priority lanes and move on. In this embodiment, the stretch of road 2 preceding the traffic light will have five additional vehicle stop lines inscribed denoting the position at which each car must come to a stop during a red light. Thus, when the traffic light turns green, a total of 20 vehicles (4 lanes with 5 vehicles per lane) will be spaced at appropriate intervals such that they may accelerate a similar rate. Thus, the number of vehicles that traverse the intersection during a green light is significantly increased.

Claims

1. A method for increasing the traffic flow through an intersection, comprising:

designating additional lanes in a stretch of road immediately preceding a traffic light in the intersection; and

designating the same quantity of additional lanes in a stretch of road immediately following the traffic light;

wherein when the traffic light turns red, vehicles in the stretch of road immediately preceding the traffic light come to a stop; when the traffic light turns green, the vehicles traverse the intersection in parallel and enter into the stretch immediately following the traffic light, the vehicles in priority lanes of the additional lanes in the stretch immediately following the traffic light move on, while the vehicles in non-priority lanes of the additional lanes in the stretch immediately following the traffic light slow down or stop to wait until the traffic light turns red again and the priority lanes are empty, then vehicles in the non-priority lanes safely merge into the priority lanes and move on.

2. The method of claim 1, wherein the method further comprises regulating the flow of traffic by using signs and/or traffic signals in the stretches immediately preceding and immediately following the traffic light.

3. The method of claim 1, wherein the method comprises designating additional vehicle stop lines, besides a vehicle stop line on the stretch of road immediately preceding the traffic light, to effectively partition idling vehicles in an equidistant manner such that upon the traffic signal turning green, vehicles can accelerate immediately and at a similar rate.