Traffic management system in urban and interurban roundabouts

Description

PURPOSE OF THE INVENTION

[0001] The main purpose of this invention, as explained in this descriptive report, consists of a novel traffic management system in urban and interurban roundabouts. Thus, by including in them certain elements such as external walls, underpasses, etc. the intention is to create a specimen or standard roundabout, intuitive and with simple and clear directions, serving as a model for drivers, providing a more practical, simple and safe driving, as well as, in short, obtaining thereby a notable smooth flow traffic therein. Furthermore, the traffic management system in urban and interurban roundabouts also takes greatly into account pedestrians, therefore including improvements so that they can move around roundabouts in a much more comfortable and safer way, and even without hindering vehicle traffic.

[0002] Among the technical advantages provided by the traffic management system in urban and interurban roundabouts, object of this invention, we may highlight, mainly, the fact that all vehicles driving in these roundabouts can do it in a more orderly and simple way, avoiding unnecessary collisions and making driving easier, especially when manoeuvring in one direction or the other.

[0003] Another important advantage provided by this invention is the elimination or suppression of traffic lights, which considerably reduce the efficacy of roundabouts and which cause many of the holdups taking place in cities, and also cause the constant alteration in driving (constant bursts of acceleration and braking).

[0004] Likewise, we list another technical advantage of this invention, which is the considerable reduction of noise and environmental pollution (with the subsequent energy saving).

[0005] Finally, another advantage of this invention must be pointed out, which is the contribution to a better quality of life for citizens, as it alleviates problems such as stress, breathing problems, allergies, unnecessary waste of time, etc.

[0006] In general, roundabouts are located in urban centres or even interurban areas with great traffic density; therefore, these roundabouts of large dimensions are especially found in big cities, where every year that goes by traffic problems increase several times over, with the serious consequences this implies, such as: stress in the population due to the constant holdups, especially during rush hours; greater pollution with large CO₂ concentrations caused by the action of starting, braking and having many vehicles constantly stopped (caused by traffic lights) and with the engine running; greater noise pollution; etc.

BACKGROUND OF THE INVENTION

[0007] To the present day, there are many roundabouts, circular and elliptical squares which have abundant horizontal and vertical road signs, which, far from helping when driving, what they do is make it even more complicated, with very strict directions that normally cause confusion among drivers, thus involuntarily creating black spots, that sometimes force drivers to follow an undesired direction, so instead of helping to channel road cycles in large cities, especially during rush hours, what they do is increase traffic jams, holdups, etc. thus increasing the risk of collisions, accidents, etc.

[0008] In most cases, these classic roundabouts do not properly guarantee the personal safety of pedestrians, the weakest party in the sphere of road safety, as roundabouts seem to be mostly aimed at channelling and organising road traffic than at guaranteeing the pedestrian's safety, as there is no appropriate infrastructure for this.

[0009] US2002076276 (A1) discloses a roundabout design with a central roundabout with several lanes which provides a generally outward spiralling lane design instead of a continuously circulating lane design, with. Nevertheless, in said document there are not found corner sectors or walls for delimiting said sectors.

DESCRIPTION OF THE INVENTION

[0010] With the purpose of overcoming the drawbacks stated in the preceding paragraphs, i.e., so that roundabouts, circular and elliptical squares are not communication junctions or places where excessive horizontal and vertical road sighs, excessive traffic light regulation, as well as an inappropriate approach of their features, far from making driving easier, rather complicate it even more, by means of very strict directions that usually cause confusion among drivers, for all these reasons, a traffic management system in urban and interurban roundabouts has been devised, which is the object of this invention, which carries out a real organising and channelling function for road traffic, resulting in a notable smooth flow of traffic, as well as guaranteeing the pedestrian's safety.

[0011] The described system includes several elements, such as lane separating walls (figs 1-4) allowing to trace different routes for each of the roundabouts accesses. These walls (1) have a semicircular shape (they may also have a more linear shape although it is less practical for traffic) and are placed in each of the angles or corners, starting each of them from a point of the road close to the intersection, following towards the roundabout (even entering it) and ending in a point of the other road located to the right, and more or less at the same distance from the intersection. The aim is to subdivide a roundabout in several sectors, in such a way that it would be delimited in the following way: an internal or central roundabout, made up of the traffic island and a circular ring preferably of two or three lanes (2); and several sectors (3) located in each of the corners and which are each delimited by the lane separating walls (1). With all this, we could say that in these roundabouts there is a central part or internal roundabout and a part made up of the different sectors going along the central part in each of the corners or angles and called peripheral roundabout. These lane separating walls (1) will preferably be build of concrete, although they can also be designed using materials of a varied nature (with plastic pillars, using gardening materials, etc.); besides, they should not be too high so as not to hinder drivers' visibility.

[0012] Another element to be highlighted is the construction of tunnels for pedestrian crossing (4), which constitutes an essential element because it contributes to the elimination of a great deal of holdups taking place daily caused by pedestrians when they cross the road on the surface. These tunnels (4) include accesses that would be located in each of the corners (5), and which must be provided both with stairs and ramps (or lifts) to be used by cyclists and disabled persons as well. These tunnels (4) may offer two different routes with four accesses each. The first route, with a classic design (fig 1) consisting in perpendicularly crossing each of the roads. The fact of using four accesses allows the pedestrian to go from one tunnel to another with no need to necessarily go outside to re-enter the other tunnel, apart from the saving meant by not having to build twice as many accesses (two for each road). The second (fig 2) I think is more innovative and consists of building tunnels starting at the same accesses as in the previous design, but going towards the centre of the roundabout (6) and all being linked with each other. This design with a cross shape is more practical than the previous one, as it allows the pedestrian to go towards the centre and, from there, take the desired direction in a more practical way. That way, even though the pedestrian has to cover a few more metres (compared to the previous design) to go from the starting point to the closest points, many metres can be saved when going to the furthest point (as one goes diagonally and more directly). Furthermore, with the second design, the central part can be fitted out with different spaces (7) for business rental (newsstand, tobacconist's, bar, etc.), toilets or council use (store fences, signs...), etc. These tunnels may also be equipped with surveillance cameras and alarms for greater pedestrian security.

[0013] It must be pointed out that the construction of tunnels (4, 6) implies a prior study of the sewer system (if it goes through the centre of the roundabout), in case if was advisable to divert it along the tunnel area (4) so that the latter can be built next to the road without coming up against any large obstacle, so that pedestrians have to go down as few metres as possible. Although they could also be built with no need to divert the sewer system, but it would have to be in the form of a gradual ramp, starting from an access with as little depth as possible and going down towards the centre with as little slope as possible, so they would go underneath the sewer system (or other minor obstacles) with no need to divert the sewers.

[0014] In case for any reason there is no interest in providing the roundabouts with tunnels (4, 6), there is a possibility of creating the roundabouts with raised zebra crossings (figs 3-4). This design is less ambitious than the previous ones (there is no need to build tunnels) but poses more problems, both for drivers and pedestrians, thereby reducing the efficacy of roundabouts. This is the cheapest option of all and in order to have the best guarantees, it is necessary to fit out these roundabouts with certain basic elements and mechanisms. Firstly, zebra crossings should be raised (8) to force all vehicles to drive slowly and even forcing them almost to brake when arriving to the pedestrian crossing. Another aspect to be highlighted is that these raised zebra crossings (8) should be located at a minimum distance of about ten metres from the intersection. With that, the aim is that vehicles leaving the roundabout and stopping at the following pedestrian crossing are not held up (in general) within the circular lanes of the central part or internal roundabout (2) which would cause a tailback effect due to the concentration of vehicles, thus causing a constant jamming within the central ring that would directly affect all the roundabout accesses, causing unnecessary hold ups in all roads. This usually happens in many roundabouts in which zebra crossings are very close to the intersection which forces drivers to stop always within the ring, constantly blocking the whole roundabout. On the other hand, having these crossings a little away from the intersection also implies less visibility for drivers, which forces to provide roundabouts with safety measures, such as: precaution fire lights (intermittent amber, but which may turn red only if they detect that a vehicle approaches at a speed higher than the one permitted) to warn drivers that they do not have priority; signs in the curves of the peripheral roundabout, warning drivers of the existence of the pedestrian crossing; vertical signs with the speed limit (40 km/h before arriving to the intersection and 20 km/h once within it, for example); horizontal indications painted on the road, etc.

[0015] Raised pedestrian crossings (8), for large roads, are subdivided in blocks of no more than two lanes so that pedestrians can cross large roads with greater control over the vehicles that stop as they cross and vice versa, to give drivers better visibility and control over the pedestrians who cross before them.

[0016] Finally, it is also possible to build roundabouts with a combined design. For example: a main road with four or five lanes in each direction and provided with underpasses for pedestrians, that crosses a quieter road (with one or two lanes in each direction) and provided with raised zebra crossings. Another possibility is building roundabouts with tunnels and with zebra crossings (not raised). These zebra crossings would only be used from a certain time during the night (for security reasons for pedestrians) during which tunnels would be closed, as they would not be as necessary when the traffic becomes free-flowing, outside rush hours. For that, zebra crossings would be regulated with traffic lights that would turn red (only for about 20 seconds) and only on request from pedestrians; the rest of the time they would work only as precaution traffic lights (intermittent amber). During the day, zebra crossings would remain closed with traffic lights exclusively for pedestrians (permanent red) and with timetable indications, or they could even have some kind of gate-fence (in case it was decided to put fences around the corners so that pedestrians do not cross), that would open at the authorised time at the same time that tunnel accesses would be closed. In order for this to be more practical, it would be important that all gates (tunnels and zebra crossings) could be opened and closed with the same key, to make the task easier for the authorised personnel. For the use of these (night use) zebra crossings, it would also be necessary to have good illumination in roundabouts, especially for pedestrian crossings.

[0017] The inclusion of traffic light posts within large roundabouts is incompatible with the latter, although in the way they are created currently, they are necessary due to the large volume of vehicles entering the four-five lane ring. What is paradoxical is why there are so many traffic lights installed in medium-sized roundabouts that are only a waste of time and exasperate drivers needlessly (especially during rush hours). With this new traffic management system in urban and interurban roundabouts, by means of the subdivision with lane separating walls (1), while eliminating a great number of zebra crossings if they are replaced with tunnels (4, 6), the aim is to eliminate traffic lights (and if there are any, only precaution ones), since the vehicles driving within would do it in a safer, orderly way with fewer obstacles when manoeuvring. The fact that these traffic lights are within the ring, forcing a great number of vehicles coming from all directions to stop at all times, already causes many of the problems that take place constantly. Furthermore, one of the great advantages of the described system is the option it gives all drivers circulating in any of the roads toward the intersection to turn right with no need to enter the central ring and without having to give way (only in case there is a pedestrian crossing). This already considerably relieves roundabouts of a constant concentration of vehicles that at present are trapped within them.

[0018] Another important advantage offered by these roundabouts is that they allow to regulate traffic much better, especially at times and periods of greater road traffic congestion when great problems take place, such as: the beginning and the end of holidays, festivities (with great concentrations of people and streets closed to the traffic), rush hours, etc. Subdividing a roundabout in accesses of two or three lanes at most, makes it possible, at the most difficult times, to give way to vehicles coming from an extremely busy road so that they can enter the central ring and thus avoid in this road endless holdups which are more and more common. This can be achieved in different ways:

1) By placing a fence (9), or by placing bollards that rise and hide automatically in one of the lanes coming out into the internal roundabout and that are part of the non busy roads. That way, many more vehicles from the busy road than from the other roads would circulate in the internal roundabout. These fences (9) should be clearly visible and include an arrow forcing vehicles to enter the lane on the left and to give way, which would cause a funnel effect that would prevent large numbers of vehicles coming from the non busy road from entering the internal roundabout, in favour of those coming from the busy road. These fences could be stored in a reserved space (7) that would be located within the underground surface reserved for pedestrians; that way the task of the authorised personnel would be easier, as they would not have to carry the fences every time for each of the roundabouts.

2) Another option is to install sensors that would be located in each of the roads towards the roundabout. These sensors would be installed at an approximate distance of 50 to 100 metres and would be used to detect if there are vehicles stopped on the road for 30 seconds, for example. Whenever this happened, traffic lights (located before zebra crossings, if any) would be activated and would start working so that the other accesses are not saturated. These traffic lights, for example, would alternate between red and amber intermittently, and with frequency of around 30 seconds. This would also clear accesses with maximum saturation, as they would more easily enter the internal ring. Later, whenever sensors detected that during 30 seconds (for example) no vehicles are stopped, they would automatically deactivate traffic lights, that would start working as precaution traffic lights (only intermittent amber).

[0019] It is therefore the object of this invention to offer a novel traffic management system in urban and interurban roundabouts, which, by including within roundabouts certain elements such as external walls, underpasses or underground tunnels, raised zebra crossings, aims at creating a specimen or standard roundabout, intuitive and with simple and clear directions, serving as a model for drivers, providing a more practical, simple and safe driving, as well as, in short, obtaining thereby a notable smooth flow traffic therein. Furthermore, the described system also takes pedestrians greatly into account, including improvements so that they can move around roundabouts in a much more comfortable and safer way, and even without hindering vehicle traffic. Furthermore, the described system tries to eliminate to a large extent CO2 emissions that are uselessly emitted to the atmosphere because vehicles are stopped for long periods of time due to daily holdups.

DESCRIPTION OF THE DRAWINGS

[0020] In order to complete the description carried out and with the purpose of making the understanding of the invention characteristics easier, a set of drawings is enclosed to this descriptive report, in which, as a way of example, but not limited to, the following has been represented:

Figures 1 and 2 show a ground view of roundabouts where the system object of this invention is applied. The difference between figure 1 and figure 2 is the design of the pedestrian tunnels with four accesses for each roundabout but with different routes.

Figure 3 shows a schematic view of a roundabout where the described system is applied, but without pedestrian tunnels and provided with raised zebra crossings.

Figure 4 shows a view of a medium-sized roundabout with raised crossings and without pedestrian tunnels, which are not so necessary to cross two or three lane roads, unlike large roundabouts.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] As can be seen in the drawings mentioned, the traffic management system in urban and interurban roundabouts includes a series of elements such as lane separating walls (1), which channel more safely vehicle traffic, circular ring of two or three lanes (2), subdivision of sectors (3), in such a way that it would be delimited in the following way: an internal or central roundabout, made up of the traffic island and of a circular ring preferably of two or three lanes (2); and several sectors (3) located in each of the corners, each of them delimited by the lane separating walls (1), forming a kind of peripheral roundabout. Underground tunnels or underpasses (4, 6), which would have stairs or ramps (or lifts) to be used by cyclists or disabled persons (5), space in the roundabout basement (7) to store fences or signs, raised zebra crossings (8), aimed at reducing the speed of vehicles approaching them, fences (9), thus the inclusion of these elements in the described system allows a better efficacy of roundabouts in their function of making driving easier and make them more driveable, and all in all, achieve a greater performance in roundabouts, and likewise reduce CO₂ pollution rates

Claims

1. TRAFFIC MANAGEMENT SYSTEM IN URBAN AND INTERURBAN ROUNDABOUTS, characterised in that in the roundabouts where it is applied it includes certain elements, including lane separating walls (1), which channel more safely vehicle traffic, circular ring of two or three lanes (2), subdivision of sectors (3), in such a way that the roundabout is delimited in the following way:

• an internal or central roundabout, made up of the traffic island and of a circular ring preferably of two or three lanes (2); and

• several sectors (3) located in each of the corners, each of them delimited by the lane separating walls (1), forming a kind of peripheral roundabout.

2. TRAFFIC MANAGEMENT SYSTEM IN URBAN AND INTERURBAN ROUNDABOUTS, according to claim 1, characterised in that the traffic management system comprises underground or underpasses that define two different possible routes:

• A first one with a classic design (4), in which the roads cross each other roads perpendicularly; and

• a second one according to a second design, consisting in the construction of tunnels starting from the same accesses as the previous design but going towards the centre of the roundabout, in the form of a cross (6) and all being connected there among them.

3. TRAFFIC MANAGEMENT SYSTEM IN URBAN AND INTERURBAN ROUNDABOUTS, according to any of the claims 1 to 2, characterised in that the roundabout is built without tunnels for pedestrians, so there such roundabout is provided with raised zebra crossings (8), and is also equipped with basic safety mechanisms, such as: construction of zebra crossings at a minimum distance of about ten metres from the intersection to avoid blocking the central ring; precaution traffic lights (intermittent amber but which can turn red if a vehicle approaches at a speed above the one permitted) to warn drivers that they do not have priority; signs in the curves of the peripheral roundabout, warning drivers of the existence of the pedestrian crossing; speed limit signs (40 km/h before arriving to the intersection and 20 km/h within it, for example); painted indications on the road; good illumination; etc.

4. TRAFFIC MANAGEMENT SYSTEM IN URBAN AND INTERURBAN ROUNDABOUTS, according to any of the claims 1 to 3, characterised in that it also comprises roundabouts with a combined design such as, for example, a main road with four or five lanes in each direction and with tunnels for pedestrians (4), meeting another less busy road (with one or two lanes in each direction) and provided with raised zebra crossings (8).

5. TRAFFIC MANAGEMENT SYSTEM IN URBAN AND INTERURBAN ROUNDABOUTS, according to any of the claims 1 to 4, characterized by comprising underground tunnels or underpasses (4,6), having stairs or ramps (or lifts) to be used by cyclists or disabled persons (5), space in the roundabout basement (7) to store fences or signs, raised zebra crossings (8), aimed at reducing the speed of vehicles approaching them, fences (9), regulating traffic depending on whether it comes from busy or non busy roads.

Ansprüche

1. Verkehrsleitsystem in Kreisverkehren in Städten und zwischen Städten, dadurch gekennzeichnet, dass es in den Kreisverkehren, wo es angewendet wird, bestimmte Elemente enthält, einschließlich Spurtrennwänden (1), welche den Fahrzeugverkehr sicherer kanalisieren, eines kreisförmigen Rings mit zwei oder drei Spuren (2), eine Unterteilung von Abschnitten (3), so dass der Kreisverkehr folgendermaßen begrenzt ist:

• ein innerer oder zentraler Kreisverkehr, der aus der Verkehrsinsel und aus einem kreisförmigen Ring, vorzugsweise mit zwei oder drei Spuren (2), besteht; und

• mehrere Abschnitte (3), die in jeder der Ecken liegen, wobei jeder davon durch die Spurtrennwände (1) unter Bildung einer Art peripherer Kreisverkehr begrenzt ist.

2. Verkehrsleitsystem in Kreisverkehren in Städten und zwischen Städten nach Anspruch 1, dadurch gekennzeichnet, dass das Verkehrsleitsystem eine Untergrundbahn oder eine Unterführung umfasst, die zwei unterschiedliche mögliche Routen definieren:

• eine erste Route mit einer klassischen Gestaltung (4), in welcher sich die Straßen gegenseitig senkrecht kreuzen; und

• eine zweite Route nach einer zweiten Gestaltung in Form eines Kreuzes (6), die aus dem Bau von Tunneln angefangen von denselben Zugängen wie bei der vorherigen Gestaltung besteht, aber zum Zentrum des Kreisverkehrs hin verläuft, und wobei alle Elemente dort miteinander verbunden sind.

3. Verkehrsleitsystem in Kreisverkehren in Städten und zwischen Städten nach einem der Ansprüche 1 oder 2, dadurch gekennzeichnet, dass der Kreisverkehr ohne Tunnel für Fußgänger gebaut ist, so dass dort dieser Kreisverkehr mit erhöhten Zebrastreifen (8) versehen ist und auch mit Grundsicherheitsmechanismen ausgestattet ist wie: dem Bau von Zebrastreifen in einem Mindestabstand von ungefähr zehn Metern von der Kreuzung, um ein Blockieren des zentralen Rings zu verhindern; Sicherheitsverkehrslichtern (blinkendes gelbes Licht, was jedoch rot werden kann, wenn sich ein Fahrzeug mit einer Geschwindigkeit über der erlaubten Geschwindigkeit nähert), um Fahrer zu warnen, dass sie keine Vorfahrt haben; Schildern in den Kurven des peripheren Kreisverkehrs, die Fahrer vor dem Vorhandensein des Fußgängerübergangs warnen; Geschwindigkeitsbegrenzungsschilder (z. B. 40 km/h vor der Ankunft an der Kreuzung und 20 km/h innerhalb letzterer); aufgemalte Angaben auf der Straße; eine gute Beleuchtung; usw.

4. Verkehrsleitsystem in Kreisverkehren in Städten und zwischen Städten nach einem der Ansprüche 1 bis 3, dadurch gekennzeichnet, dass es auch Kreisverkehre mit einer kombinierten Gestaltung umfasst, wie zum Beispiel eine Hauptstraße mit vier oder fünf Spuren in jeder Richtung und mit Tunneln für Fußgänger (4), die auf eine weitere Straße (mit einer oder zwei Spuren in jeder Richtung) trifft, die weniger frequentiert ist und die mit erhöhten Zebrastreifen (8) versehen ist.

5. Verkehrsleitsystem in Kreisverkehren in Städten und zwischen Städten nach einem der Ansprüche 1 bis 4, dadurch gekennzeichnet, dass es Untergrundtunnel oder Unterführungen (4, 6), die von Radfahrern oder Personen mit Behinderungen (5) zu benutzende Treppen oder Rampen (oder Aufzüge) aufweisen, Raum in dem Kreisverkehruntergeschoss (7) zum Aufbewahren von Zäunen oder Schildern, erhöhte Zebrastreifen (8), die dazu bestimmt sind, die Geschwindigkeit von Fahrzeugen, die sich diesen nähern, zu verringern, Zäune (9), die den Verkehr regulieren, je nachdem, ob er von hoch frequentierten oder weniger frequentierten Straßen kommt, umfasst.

Revendications

1. Système de gestion de la circulation dans les ronds-points urbains et interurbains, caractérisé en ce que dans les ronds-points où il est appliqué il inclut certains éléments, y compris des murs de séparation de voies (1), qui canalisent plus sûrement la circulation des véhicules, un anneau circulaire à deux ou trois voies (2), une subdivision de secteurs (3), de telle manière que le rond-point est délimité de la manière suivante :

• un rond-point interne ou central, fait d'un îlot de circulation et d'un anneau circulaire de préférence à deux ou trois voies (2) ; et

• plusieurs secteurs (3) localisés sur chacun des coins, chacun d'eux étant délimité par les murs de séparation de voies (1), formant une sorte de rond-point périphérique.

2. Système de gestion de la circulation dans les ronds-points urbains et interurbains, selon la revendication 1, caractérisé en ce que le système de gestion de la circulation comprend des souterrains ou des passages souterrains qui définissent deux différentes routes possibles :

• Une première avec une conception classique (4), dans laquelle les routes se croisent entre elles perpendiculairement ; et

• une deuxième selon une deuxième conception, consistant en la construction de tunnels partant des mêmes accès que la conception précédente mais allant vers le centre du rond-point, sous la forme d'une croix (6) et tous y étant connectés entre eux.

3. Système de gestion de la circulation dans les ronds-points urbains et interurbains, selon l'une quelconque des revendications 1 à 2, caractérisé en ce que le rond-point est construit sans tunnels pour les piétons, de sorte qu'un tel rond-point est pourvu de passages piétons surélevés (8), et est aussi équipé de mécanismes de sécurité de base, tels que : construction de passages piétons à une distance minimum d'environ 10 mètres de l'intersection pour éviter de bloquer l'anneau central ; feux de circulation préventifs (jaune intermittent mais qui peut passer au rouge si un véhicule s' approche à une vitesse au-dessus de celle autorisée) pour prévenir les conducteurs qu'ils n'ont pas la priorité ; panneaux dans les courbes du rond-point périphérique, prévenant les conducteurs de la présence du passage piéton ; panneaux de limitation de vitesse (40 km/h avant d'arriver à l'intersection et 20 km/h au sein de celle-ci, par exemple) ; indications peintes sur la route ; bon éclairage ; etc.

4. Système de gestion de la circulation dans les ronds-points urbains et interurbains, selon l'une quelconque des revendications 1 à 3, caractérisé en ce qu'il comprend en outre des ronds-points avec une conception combinée telle que, par exemple, une route principale avec quatre ou cinq voies dans chaque direction et avec des tunnels pour les piétons (4), rencontrant une autre route moins encombrée (avec une ou deux voies dans chaque direction) et pourvue de passages piétons surélevés (8).

5. Système de gestion de la circulation dans les ronds-points urbains et interurbains, selon l'une quelconque des revendications 1 à 4, caractérisé en ce qu'il comprend des tunnels souterrains ou des passages souterrains (4, 6), ayant des escaliers ou des rampes (ou des ascenseurs) destinés à être utilisés par des cyclistes ou des personnes handicapées (5), un espace au sous-sol du rond-point (7) pour stocker des barrières ou des panneaux, des passages piétons surélevés (8), visant à réduire la vitesse des véhicules à leur proximité, des barrières (9), régulant la circulation selon qu'elle vienne de routes encombrées ou non encombrées.

Drawing