ES2784464A1 - Traffic signaling and regulation system and procedure for roundabouts (Machine-translation by Google Translate, not legally binding) - Google Patents

Abstract

Vehicle access control system and procedure to roundabouts based on matching their speeds, grouping the vehicles at each access into squads and appropriately staggering the arrival times of the squads from the two perpendicular directions of access to the roundabout. It uses vertical visual marking in the form of circular light sectors to indicate the allocation of access priorities. The vehicle platoons are formed by means of luminous platoon head signs located on the sides of the entrances and/or transversely on the ground of the entrances. These signals move at a constant speed, synchronizing the entrance to the roundabout of the vehicle platoons from every two accesses from opposite directions. The perpendicular direction signs have a spatial and temporal offset adjusted to match the arrival of vehicles in the roundabout access pair with the start of their access priority. (Machine-translation by Google Translate, not legally binding)

Description

DESCRIPTION

Traffic signaling and regulation system and procedure for roundabouts

Technical sector

The present invention falls within the field of vehicle traffic control and more specifically refers to a system and procedure for regulating the access and circulation of vehicles in roundabouts by means of optical signaling at the entrances and in the roundabout, sensors to monitor traffic and processing unit for control.

State of the art

A roundabout or roundabout is a circular intersection where traffic travels in only one direction around a central island. Roundabouts have many advantages over intersections or crossings, including having fewer points of conflict between vehicles by restricting the turns allowed to vehicles. In modern roundabouts, the vehicles that circulate through the roundabout have priority over the vehicles that access it, so the vehicles that access it must yield and stop if necessary in case of conflict with the vehicles that circulate through the roundabout.

Although roundabouts increase safety and reduce transit times when compared to conventional intersections (crossings), they still have limitations such as: low effective capacity because drivers require a significant (and highly variable) interval (“gap”) of time between vehicles to decide to join the roundabout and reach sufficient speed, possibility of capturing the roundabout for long periods of time due to the predominant traffic of an access, all of this as a consequence of the frequent need to completely stop vehicles at the accesses to the roundabout, which they then have to compete to enter with the vehicles that circulate through it with a speed of between 35 and 60 km / hour, thus requiring much more space between vehicles (gap) and increasing insecurity.

Various roundabout designs are known to improve the capacity or safety of roundabouts [https://en.wikipedia.org/wiki/Roundabout]. Among them, the physical design of turbo rounds is known ["Turborotonde en turboplein: ontwerp, capaciteit en veiligheid" (Turbo Roundabout and Turbo Circle; Design, Capacity and Safety) (in Dutch). Delft University of Technology. 8 January 2013], which seek to reduce the number of conflict points in roundabouts.

The design of [Novotny, WO2014 / 094693 A1, Circular intersection with lighted warning device] is also known, in which a roundabout with a central luminous ring is proposed with two operating modes: either it is turned on in sequence, so that the The lights move in the direction of the vehicle's turn in the roundabout or flash to indicate caution.

For autonomous vehicles, Reza Azimi's proposals and studies to control the flow of autonomous vehicles at intersections and roundabouts [US 2013/0304279 A1] [R. Azimi, G. Bhatia, R. Rajkumar, P. Mudalige “STIP : Spatio-Temporal Intersection Protocols for Autonomous Vehicles ”ACM / IEEE 5th International Conference on Cyber-Physical Systems (ICCPS), 2014] [R. Azimi, G. Bhatia, R. Rajkumar, P. Mudalige“ V2V Intersection Management at Roundabouts ” Society for Automotive Engineers (SAE) World Congress, Apri 2013, Detroit, MI, USA].

There are various technologies and standards that try to optimize, make safer and improve traffic in roundabouts, intersections and other environments through electrical communications between each vehicle and the environment, encompassed in the V2X (vehicle to everything) concept [https: // en .wikipedia.org / wiki / Vehicle-to-everything] that includes both communication between vehicles, vehicles and road infrastructure or vehicles and pedestrians. Mobile technologies such as 3GPP contemplate electrical communications for these applications [3GPP1] 3GPP TS 23.285 v15.0.0. Architecture enhancements for V2X Services. Release 14 (March 2018).

[3GPP2] 3GPP TR 22.186 V15.2.0, Technical specification group services and system aspects. Enhancement of 3GPP support for V2X scenarios. Release 15 (September 2017). [ETSI1] ETSI EN 102 637-2 v1.3.1, It S; Vehicular Communications; Basic Set of Applications; Part 2: Specification of Cooperative Awareness Basic Service (2014).

These autonomous vehicle coordination technologies (self-driving) are not applicable when driving conventional vehicles with a driver, so it is necessary to improve the performance and safety of roundabouts through procedures that are applicable to both driver and autonomous vehicles. For this reason, the present invention mainly uses optical signaling, understandable by all types of vehicles and driving systems, for the coordination of vehicles in the accesses and circulation through the roundabout, without prejudice to the fact that this optically transmitted information can also be transmitted via radio to devices housed in the vehicles.

Description of the invention

The circulation in the current roundabouts presents several important problems that limit the flow and safety of the traffic. Two parameters determine, apart from the geometry of the roundabout, the capacity of each roundabout: the critical interval and the interval between successive vehicles. Many roundabout capacity calculation systems [HIGHWAY CAPACITY MANUAL (HCM) (2010). Transportation Research Board of the National Academies. Washington, D.C.], [USA.TANNER, J. (1967): The capacity of an uncontrolled intersection. Biometrica, 54 (3 and 4), pp. 657 - 658] are based on the theory of acceptance of the critical gap or interval: a user located at an entrance will access the ring road if he considers that there is a sufficient gap. You must decide between taking advantage of a dangerous short gap to enter, minimizing delay and increasing risk, or wait, reducing risk and increasing delay. The hole acceptance theory uses two basic concepts: the size of the holes in the ring road and their distribution, and the usefulness of the holes for drivers. The degree of utility of the gaps for drivers can be evaluated by the two mentioned variables: the critical interval and the interval between successive vehicles.

The critical interval is a random variable measured in units of time and that represents the minimum interval (or gap between vehicles) that must exist between two vehicles that circulate on the ring road for a vehicle waiting to decide to join.

The interval between successive vehicles is defined as the time that elapses between the incorporation of a vehicle from one access and the incorporation of the next, taking advantage of the same gap, and in such a way that both vehicles are initially in a queue waiting for said gap.

These two intervals limit the capacity of the roundabouts. The critical interval (critical gap, if expressed in time), is large, highly variable and difficult to estimate, observing values of between 3 and 6 seconds, which produce a large spacing between vehicles in the roundabout. This spacing is not used efficiently by the vehicles that are incorporated because, If two vehicles join in a row, they will do so separated by at least the interval between vehicles, reducing the use of the gap and the probability that the gap will be accepted by the driver of the second vehicle to join. The value of the critical interval is large to a large extent because the vehicles that access the roundabout are often stopped at the entrance and have to reach the average speed of the roundabout in the short time available (between 30 and 60 km / hour approximately ) so as not to create dangerous situations.

The interval between successive vehicles has an observed value of between 2 and 3 seconds, also produced by the delay from when the driver sees the preceding vehicle start until it actually starts and acquires the same speed as the preceding vehicle.

As a consequence of the critical interval, the dominant traffic of one access, arriving continuously with little spacing between vehicles, can monopolize the use of the roundabout for long periods of time, creating congestion in the other accesses.

The invention can be briefly explained as a system for signaling and control of synchronous roundabouts, based on platoons of vehicles orthogonally out of phase. The present invention describes a control system and procedure for vehicle access to roundabouts that increases the safety and performance of roundabouts by forming compact platoons of vehicles that access the roundabout with uniform speed and simultaneously to accesses from both directions. from one direction (eg North and South) but the vehicles from the entrances orthogonal to said direction (eg East and West, orthogonal to North and South) arriving out of phase with respect to them by a distance of approximately the half length (or less) than the circumference of the roundabout on its central axis. The entry speed is standardized to a value approximately equal to that of the traffic circulating in the roundabout and the platoons are appropriately staggered in space and time by means of mobile platoon head signals and sector access priority signals rotary switches that allow the drivers of each access to anticipate their next priority interval in an analog way. In this way, incorporations of a complete platoon (for example 8 vehicles in two rows of four) are possible to the roundabout in the duration of a single signaling phase, through two opposite accesses simultaneously. The uniform speed and the synchronization of the arrival of vehicles with the priority avoid many stops at the entrance of the roundabout. The incorporation of the vehicles to the roundabout is carried out with less distance between them and in a much safer way since the accelerations and decelerations of the participating vehicles are very small, producing the braiding of the vehicle platoons with very small relative speeds, which which increases security.

It is important to note that not only are conflicts between vehicles to enter the roundabout regulated and minimized by means of signaling, but conflicts to exit the roundabout are avoided, when only vehicles with the same access are circulated in the same sector of the roundabout , similar to what happens in a revolving door of people.

Brief description of the drawings

Figure 1 shows a roundabout equipped with signaling devices.

Figure 2 shows a block diagram with the components of the traffic signaling and control system.

Figure 3 shows the roundabout with the stop lines and vertical signs for each sector as seen by the accessing vehicles, with their access identifier (N; S; E; O) and color and pattern, as well as the fixed bottom access sector.

Figures 4 to 28 show, for the embodiment, the cyclical sequence of signaling and access of the vehicles of the North and South entrances, followed by the East and West.

Figure 29 shows a summary of the evolution of the roundabout signage for the embodiment.

Figure 30 shows the road sign for the beginning of the squad area.

Figure 31 shows the road sign at the end of the platoon zone.

Method of implementation 1

An embodiment of the invention is described in which each sector, with its own color and pattern, is associated with an access and, when it passes in front of the associated access, it indicates the priority of access to the roundabout. In addition to having their own color and pattern, these sectors and entrances are identified, for clarity, as North, South, East and West entrances and sectors.

Figure 1 shows a roundabout equipped with vertical luminous signaling devices (12, 13, 16, 17 and 18) located at the entrances to the roundabout and on the central island (10).

Around the central island (10) there is a luminous ring (11) formed by a set of programmable colored lights that shows several circular sectors of horizontal color, which rotate at a speed similar to the average speed of vehicles on the road. roundabout. The vertical panels serve to show the vehicles at each access the position of the sectors of the central light ring. The panels contain a circle (14) in which the same colored circular sectors (15) are shown, replicating the position of the sectors of the ring, but from the point of view of the vehicles that arrive at the roundabout for each access, as would result if the ring (11) were placed vertically perpendicular to each of the entrances.

Figure 2 shows the complete traffic control system, which includes a processing unit (21) that communicates with the video camera control (22), the vertical light panels (23) and the vehicle sensors (24). The light signals (25) for the start of the platoon located at the entrances are also controlled by the processing unit and indicate at all times the front limit of the vehicle platoon.

The processing unit obtains the characteristics of the traffic: intensity, average speed, degree of grouping, from the data of the sensors and video cameras and, depending on this, modifies or not the speed of movement of each approach light signal, the absolute duration and relative of the sectors and the speed of rotation of the sectors in the panels and in the central luminous ring. The maximum width of the sectors is, by default, 180 degrees, and the processing unit extends or decreases their duration depending on the traffic detected by the sensors and video cameras.

When the sensors and / or cameras detect the beginning of the formation of a queue in some access, the size of the corresponding access sector is increased to facilitate the elimination of the queue, giving priority to preventing the arrests of the platoons at the accesses of more traffic.

Vehicles that have to turn 90 degrees to the right must enter the roundabout from the right lane. Vehicles going straight (second exit, 180 degrees) can use the right or left lane of the access. Vehicles that are going to turn 270 degrees (turn to the left) must necessarily take the left access lane. In this embodiment, a 360 degree turn (direction change) in the roundabout is not contemplated, but it is feasible, increasing the distances between vehicle platoons. In this embodiment, if a vehicle remains in the roundabout after its 270 degree turn, it loses its priority and must give way to those entering the roundabout. The same would happen to 360 degrees if 360 degree rotation were allowed.

This restriction of the entrance lane to be used by vehicles according to their exit, together with the zoning of priorities in the roundabout, which makes the vehicles circulate compartmentalized according to their entrance access, avoids conflicts between vehicles to exit the roundabout, so frequent in standard roundabouts when, when passing in front of an access, the vehicle on the outer lane of the roundabout wishes to continue in the roundabout and the vehicle on the inner lane wishes to exit through the nearby access, crossing the paths of both vehicles and forcing the deceleration of one of them.

The illuminated panels of each access show the information of the central luminous circle in the way that is most relevant to vehicle drivers: the color and pattern associated with that access, the turning position of the sector that assigns priority to the access, with the size total that reaches when that sector is fully deployed and a fixed circular sector of about 60 degrees (33) (the lower sector of the vertical circle), which visualizes the priority situation of that access through the conventional colors of green or flashing yellow or red. When the luminous sector of that access enters that sector, the common surface (intersection) to both is shown in green (v).

Figure 4 shows the mobile luminous platoon head signals (32), located on the sides of the access and / or on the ground and that are illuminated sequentially, moving

the light in the direction of travel at the recommended speed of access to the roundabout and that indicate the position of the head line of the platoon of vehicles not to cross. To form the platoons of vehicles of the appropriate size (eg, two rows of four vehicles), the dynamic lines of the platoon head are initially (at the beginning of the platoon circulation zone delimited by the sign in figure 30) separated by one distance of approximately 40 meters and, as they approach the roundabout, the platoon lines closest to the roundabout increase their speed, in order to increase the distance between platoons until they reach the necessary distance for the correct operation of the roundabout without need of arrests, all controlled by the central processing unit. This distance between platoon heads is, in the case of platoons of four vehicles, a distance equivalent to the length of the central circumference of the roundabout (line separating the two lanes) plus approximately 35 meters. The maximum number of consecutive vehicles for each row of the platoon depends on the dimensions of the roundabout and drivers are informed on the sign in figure 30.

Figure 4 schematically shows the initial moment of the signaling in which the ring and the illuminated panels indicate the immediate beginning of the access priority for the North and South entrances, since their respective semicircular sectors N and S begin to cross the sector of its access (33). The vehicles from the North and South entrances may, therefore, begin to pass their stop line (31). The stop lines are located at a certain distance from the roundabout, so that, in the event of forced stopping due to not having priority, vehicles can reach the speed of the roundabout when they reach it. In figure 5 The lower sector is displayed with its green left part (v), informing the vehicles of the North and South accesses that they have access priority. This lower sector continues to be shown in green until figure 11, in which it is about to disappear, when the passage of the semicircular sectors of North and South priority through their respective accesses is completed. North and South access vehicles reach the edge of the roundabout and figures 5 to 13 show how they circulate freely through it during the duration of their sector, having completed their access priority in figure 11, thus ceasing to access to the roundabout.

Figure 12 shows the starting time of the priority for the entrances with the appearance of the East and West sectors when the East and West sectors reach the lower sectors of the East and West entrances respectively in the vertical luminous panels. In figures 14 to 20 it can be seen how the lower sector in the East and West panels lights up in green starting from its left part (figure 14), coinciding with the passage of the East sector through the lower sector and ending on its right part ( figure 20).

In the central circle, the most advanced radius in the direction of rotation of the South and North sector is fixed respectively in the West and East direction respectively, ceasing its rotation. However, the most delayed radius of the North and South sectors continues to rotate, thus beginning (figure 14) to decrease the amplitude of these sectors. The East and West sectors appear and gradually grow with the general shift in traffic and to the same extent that the North and South sectors contract. East and West access vehicles begin to access the roundabout when they have priority.

In figure 15 it can be seen how the last vehicles coming from North and South have already left from the West and the East respectively (the maximum allowed turn is 270 °, changes of direction are prohibited in the roundabout in this embodiment). The East and West light sectors gradually increase until they reach their maximum amplitude (180 ° in this embodiment) in figure 19. Figure 20 shows the end of the priority of the East and West accesses and figure 21 shows the moment when that vehicles from North and South begin to have the right of way. The entrances of the North and South sectors will appear again in green, thus starting a new cycle, as shown in figure 22 (exact starting point) and figure 23, in which part of the sector can already be seen in green. The East and West sectors decrease until they disappear in figure 28 and the North and South sectors grow until they reach 180 degrees. The cycle repeats itself indefinitely.

In figure 29 the previously described sequence of appearance, growth up to 180 °, rotation and disappearance of the light sectors that assign priority to the respective accesses is shown in a schematic and global way.

If a vehicle remains in the roundabout after turning 270 ° (the maximum turn allowed in this embodiment) (due to driver orientation error or any other cause), it immediately loses its priority, and its absence of priority is indicated by a traffic light with flashing amber light or red light, located on the outer and inner edges of the roundabout at its confluence with the next access.

The invention is a system of signals that are deployed in the roundabout and along the entrances with a sufficient distance at each access for the vehicle squads formed and adequately spaced to arrive, approximately equivalent to the circle of the roundabout plus the length of a platoon of vehicles (for example, ten vehicles in two rows of five). This zone is identified as a platoon circulation zone with a specific traffic sign that informs about this mode of circulation (constant speed platoon circulation zone), which may include limitation information in the same or separately. of minimum speeds (for example 30 or 40 km / hour) and maximum (for example 50 or 60 km / hour). Figures 30 and 31 respectively show the vertical traffic signs indicating the beginning and end of the circulation zone in squads for this embodiment.

The above description shows a mere embodiment of the invention. A person skilled in the art can quickly deduce from the description, drawings and claims that various changes, modifications and variations are possible without thereby departing from the spirit and scope of the invention, as defined in the claims.

Mode of implementation 2

In this simplified embodiment, the operation is the same as in embodiment 1, but the vertical signals of Figure 4 (33) are replaced by conventional traffic lights. The central ring informs the vehicles within the roundabout of the priority for each sector of the roundabout in a similar way. These traffic lights are located on the stop lines (31). These traffic lights have, in normal operation, phases of flashing yellow to indicate non-priority and solid green to indicate priority, depending on the access priority situation, in correspondence with the color shown by the lower sector of the sector in the mode of Implementation 1. When the priority of an access is nearing its end, the green traffic light may briefly flash green to indicate it, or display the remaining time timer, similar to that used in some traffic lights.

The development of this invention has been carried out thanks to the financing received through the TIGRE5 Project, Community of Madrid, FEDER funds.

Claims (14)

1. System for controlling the access and movement of vehicles in roundabouts that includes any of the following signaling elements: a) A luminous cylindrical ring with a vertical axis located on the central island of the roundabout, with programmable colored lights grouped in colored sectors and visible by the vehicles that circulate in the roundabout. b) Vertical luminous panels at the entrances to the roundabout, with programmable lights that show circular sectors of different colors and / or differentiated patterns. characterized by a) The sectors of the horizontal luminous ring or of the vertical panels indicate, with their color, and optionally the graphic pattern of the color sector, that the access vehicles to the roundabout associated with that color and pattern have the priority access to the sector and of circulation by the sector of the adjacent roundabout at that moment with the luminous sector. b) The colored sectors of the horizontal ring or vertical panels rotate around the center of their circle in the direction of travel. 2. System according to claim 1, in which the colored sectors have an angle of amplitude that varies over time, the total of the circle being distributed. 3. System, according to the preceding claims, with vertical illuminated panels, located at each access to the roundabout, or on the central island in front of each access, displaying, each vertical illuminated panel of an access, the rotating sectors, with the position and orientation with respect to the ground that would be perceived by placing the central luminous ring vertically in a plane perpendicular to said access. System, according to the preceding claims, in which each vertical light panel of an access shows the relative position of the rotating sector that assigns priority to said access with respect to the sector of that access. 5. System, according to the preceding claims, in which it is displayed in green, when the rotating sector that assigns priority to an access reaches the fixed lower circular sector corresponding to said access, the area that is common to the lower sector of access, fixed on the signage, and to the rotating sector that assigns priority. System, according to claim 1, in which the light sectors rotate in the direction of traffic at a programmable angular speed and close to the average turning speed of vehicle traffic in the roundabout, each sector delimiting the roundabout area in which the vehicles of a certain access have priority to circulate. System according to claim 1, in which the light sectors in a solid or flashing amber color indicate that access is allowed without priority when the color sector passes in front of the access. 8. System according to claim 1, equipped with luminous signaling devices on the sides of the access that are illuminated sequentially, moving the light in the direction of travel and that indicate the position of the head line of the platoon of vehicles not to be crossed. . 9. System, according to claim 1, equipped with luminous devices for signaling the access floor that move in the direction of travel and that indicate the front line of the platoon of vehicles not to be crossed. 10. Procedure to control the flow of vehicles through a roundabout that includes: a) Group the vehicles of each access into platoons by means of a luminous signal at the head of the platoon, which moves towards the roundabout at a speed close to the mean linear speed of the roundabout in its mean radius. b) Synchronize said light signals from the two entrances of the same direction and opposite directions so that they arrive at the roundabout at the same time. c) Shift the illuminated signs of the entrances of the two perpendicular directions a time approximately to that of a complete turn of the sectors of the roundabout. 11. Method according to claim 10, in which the access priorities for vehicles arriving at the roundabout are shown by means of a light signal in the form of a horizontal ring with colored rotating circular sectors that indicate that the vehicles coming from the associated access to a color they have priority to access and circulate through the sector of the roundabout in which said luminous sector is located at that moment. 12. Procedure, according to claims 10 and 11, in which vehicles arriving at the roundabout are shown a circular luminous vertical signal formed by rotating colored circular sectors, with the position and orientation with respect to the ground that would be perceived by placing vertically the central horizontal luminous ring in a plane perpendicular to said access, the passage of the sector through its associated access in the horizontal ring corresponding to the passage of the sector through the lowest position of the circle when shown in the vertical sign. 13. Procedure, according to claims 10, 11 and 12, in which the display of sectors shows in each access the rotation position at each moment of the rotating sector that assigns priority to said access, with respect to the horizontal fixed sector of the access . 14. Procedure, according to claims 10 to 12, in which it is displayed in green, when the rotating sector that assigns priority to an access reaches the lower circular sector that corresponds to the access, the common area or intersection of that sector and the sector that gives priority to access.