TRAFFIC CALMING SYSTEM

Field of the Invention

The present invention relates to a controllable traffic calming device consisting of an upper part, two ramp parts and seals located between the upper part and the ramp parts, the traffic calming device in the lowered position being substantially flush with the surrounding road surface, and in the raised position the upper part being located at a raised level and substantially parallel to the road surface, the ramp parts being positioned at an angle to the upper part and the lower parts of the ramp parts being pivotally arranged flush with the road surface .

Background Art Traffic calming devices in the form of bumps are used at a large number of places in the road network to reduce the speed along stretches of road where the ambition is that vehicles should travel at a particularly low speed, for example in the vicinity of schools, daycare centres etc. The idea of a speed bump is that road users should be alerted to the demand for lower speed and then reduce the speed of the vehicle to such an extent that the effect of the speed bump will not be greater than necessary. Studies performed indicate that physical traffic calming devices are the only active measures to ensure lower speeds. Thus they serve an important purpose in terms of reaching the goals set up by the European Union within the scope of the common traffic policy. At the same time there are a number of negative secondary ef- fects of the existing speed bumps.

An ordinary stationary traffic calming device usually consists of a raised area in the transverse direction of the road. The raised area may have an arched upper surface or a three-piece surface consisting of an

upward ramp, a plane surface and a downward ramp. A stationary traffic calming device is in most cases made of asphalt or stone. Such stationary traffic calming devices result in a reduction of the speed in the areas around the traffic calming devices, but also create great problems for buses in regular services and emergency vehicles. A bus must keep a very low speed when passing a traffic calming device so as not to cause damage to the bus, but above all repetitive strain injury to the bus driver who on countless occasions every day must pass stationary traffic calming devices. A bus driver is exposed to significantly greater physical stress than a car driver when passing traffic calming devices. The traffic calming devices also generate increased emissions since bus drivers under stress, who have a tight timetable, are forced to make vigorous accelerations after the traffic calming devices. The main drawback of the stationary traffic calming devices is, however, their effect on emergency vehicles. Paramedics cannot, for example, start the treatment in the ambulance before it is obvious that there are no traffic calming devices between the position of the ambulance and the hospital, or in any case that there are no such devices within a certain distance. The vibrations and jerks caused by the speed bumps can, in fact, cause severe injuries to patients suffering from, for instance, spinal fractures and can also damage the equipment of the emergency vehicles. As a result, patients who could be given adequate treatment in the ambulance frequently do not receive the required treat- ment until the ambulance has arrived at the hospital.

To solve the problems with the stationary traffic calming devices, there are a large number of different solutions involving flexible traffic calming devices which in their normal position are located flush with the road surface. As a rule, these solutions are based on sensors which sense a vehicle driving beyond the stipulated speed limits, in which case the traffic calming

device is raised from its normal position and thus constitutes an obstacle to the vehicle. In the prior art solutions, the sensors consist of radar, IR, pressure sensors or switches. A drawback of these solutions is that the sensors must detect the speed of the vehicle at a distance from the traffic calming device which is sufficient for the device to be raised from the ground to its obstructing position. This may imply that also a vehicle that has not been speeding will be punished by the traffic calming device being raised when a vehicle in front is positioned on or just in front of the device. Nor do these solutions solve the problem with emergency vehicles that must be allowed to pass the traffic calming devices without the paramedics having to interrupt the treatment of a patient or the like.

Practically all existing flexible traffic calming devices have a punishing effect. By punishing is here meant that the traffic calming devices are raised because a vehicle exceeds the speed limit that is valid in the area.

GB-A-2 079 356 discloses a simple design of a variable traffic calming device in which a horizontally positioned cylinder presses a vertical rod upwards when raising the traffic calming device. The traffic calming device has a timer function which controls the points of time at which the device is to be raised and when it is to be flush with the road surface. The two parts which are raised by the cylinder are the actual traffic calming member and a flap between which there is no seal. This means that, for example, melt water, gravel, salt and other dirt will be collected between these movable parts. There is also an obvious risk that an individual positioned on the traffic calming device is squeezed between the traffic calming member and the flap when the device is activated.

US-A-6 010 277 discloses a speed bump consisting of two articulated cover plates, one cover plate sliding

directly on the other cover plate which is controlled pneumatically or hydraulically . Also this solution may result in dirt etc getting between the movable parts. There is also a risk that individuals positioned on the speed bump are squeezed when the speed bump is activated.

WO-A2-2005/010845 discloses variants of punishing speed bumps and vehicle barriers . Sensors in front of the barriers can detect speed, type of vehicle and weight and, based on this detection, raise the barrier from a horizontal position. The barrier may consist of three parts, a central part which is always horizontal and two ramp parts which are arranged at an angle to the central part. Each part of the barrier is connected to a damper and a spring system, and between the different parts there are rubber seals to prevent dirt and water from getting between the parts. Since these speed bumps use a spring system and a damper for each part of the barrier, high initial costs for the equipment are incurred, and the operational reliability is reduced since there are several parts which affect the raising and lowering of the barrier and can break. There is also a risk that individuals are squeezed between the different parts when the barrier is activated.

Consequently there is a need for a traffic calming device which is easy to operate, increases the operational reliability of the traffic calming device in spite of considerable influence from dirt, water etc and which can be mounted in areas with a large number of pedestrians with no risk of their being squeezed when raising and lowering the device.

There is also a need for a traffic calming device that has a speed reducing effect on the traffic while at the same time it does not have an obstructive effect, for example, on emergency vehicles and specific heavy vehi- cles.

Summary of the Invention

The object of the present invention thus is to provide a device which solves the above problems. This object is achieved by a device which is characterised in claim 1. Advantageous embodiments are defined in the dependent claims .

Brief Description of the Drawings

The invention will in the following be described in a non-limiting way and for illustrative purposes with reference to the accompanying drawings in which Fig. 1 is a cross-section of a traffic calming device according to the invention seen from the front, Fig. 2 is a cross-sectional view of a traffic calming device in the raised position according to the invention seen from the side,

Fig. 3 is a detailed view of the transition between the upper part of the traffic calming device and a ramp part in the raised position, Fig. 4 is a detailed view of the transition between the road surface and the lower part of the ramp part, and Fig. 5 is a cross-sectional view of a traffic calming device in the raised position seen from the side accord ^¬ ing to a second embodiment of the invention.

Detailed Description of the Invention

Fig. 1 is a cross-sectional view of a traffic calming device 20 according to a first embodiment of the in ^¬ vention seen along the roadway. The traffic calming de- vice consists of an upper frame part 1 and a lower frame part 2. The upper frame part has a coating on the upper part 3 of its upper side. The upper part 3 is the part that constitutes the roadway and is preferably parallel to the surrounding roadway both in the raised and in the lowered position. In this way, the traffic calming device can also serve as a pedestrian crossing.

On both sides of said upper part there are ramps 4 and 5. The ramps are in their lower parts 4b, 5b arranged or mounted in bearings in a concrete foundation 13 and are in their upper parts 4a, 5a, facing the upper part 3, connected to the upper part only by a seal 6 in order to eliminate the risk of a person being squeezed and dirt getting into the hinge. The concrete foundation 13 is recessed in the roadway and supports the frame parts 1 and 2 and protects the entire device from being affected by the surrounding ground. In the lowered position, the three parts - the upper part 3 and the ramps 4 and 5 - are parallel and flush with the roadway or road surface. The upper part 3 and the ramps 4 and 5 are preferably made of a substantially rigid material. The two frame parts 1 and 2 are connected to a system consisting of a single-acting, or alternatively double-acting, actuator 7, sliding rods 8 and shock absorbers 9. The actuator 7 is used to move the upper frame part 1, and thus also the upper part 3, up and down in the vertical direction and preferably consists of a hydraulic piston, but may, for example, also be a pneumatic piston or bellows. As a result, the angular position of the ramp parts 4, 5 is simultaneously affected and the entire traffic calming device moves as one unit. The sliding rods serve to guide the upper frame part 1 so that it moves merely vertically. The shock absorbers 9 have a double-acting movement-equalising function in the vertical movement of the upper part 1. The hydraulic piston 7 is attached to the upper frame part 1 in a housing 10 which has an elongate clearance groove 17 located in the centre of the housing 10. The hydraulic piston 7 is operated by means of an ordinary hydraulic system consisting of a hydraulic piston and, (optionally) , an associated hydraulic tank 11. A layer 12 is applied to the exterior parts 3-5 of the traffic calming device, preferably consisting of SafeGrip™, which is a mix of a

polyurethane mixture and a ceramic stone, which results in a wear-resistant and practically non-skid surface.

In its normal position, the traffic calming device will be in the raised position. When the system is deac- tivated, the upper frame part 1 will be pulled down to the lower frame 2 to provide a flat roadway. The deactivation of the system will be described in more detail below. This movement is performed by a piston 7 pulling down the upper frame part 1. To return to the raised position, the pressure in the piston 7 is released and the return to the raised position occurs in a controlled manner, on the one hand by the springs of the shock absorbers 9 pressing up the upper frame 1 while at the same time the substance (liquid, gas) in the shock absorbers 9 prevents an excessive movement. Preferably the traffic calming device is symmetrical, that is the ramps are the same size and have substantially the same inclination in the raised position. For various reasons, one of the ramps may, however, be smaller than the other, for example if the traffic calming device is located on a hill or the like.

When a heavy truck, bus or some other large vehicle passes without the system being deactivated, the dead weight of the vehicle will press down the upper frame part 1. This movement is controlled by the springs of the shock absorbers making resistance while at the same time the material of the springs ensures that the return to the raised position takes place in a controlled manner and at an appropriate speed. In this case, the piston has no effect whatsoever on the system. The piston 7 is attached to the upper frame 1 in such a manner that a movement of the upper frame 1 to the lowered position can occur without the piston being actuated. This function is accomplished by the piston being attached to the upper frame 1 in a vertical oblong hole 17 which gives the upper frame part liberty to move the intended distance also when the piston is in its raised position.

The deactivation of the system preferably occurs by GSM or some other RF-based technology. Transmitters are placed in the vehicles which are authorised to pass deactivated (lowered) traffic calming devices. When such a vehicle approaches a traffic calming device 20, the transmitter sends a signal which is received by a decision device which is placed in the traffic calming device and which actuates a controlling device which lowers the traffic calming device to make the roadway flat for pass- ing. The decision device is a device that receives signals and can be in the form of, for instance, a detecting means for receiving electronic signals, acoustic signals, light signals or radiowaves etc. The decision device then evaluates the signal and instructs the controlling device to actuate the actuator 7 to lower the traffic calming device .

The traffic calming device can, for example, be adapted to be lowered when a vehicle provided with a SIM card that is authorised is located within a certain dis- tance from the traffic calming device and, after that, be raised when said vehicle is located beyond said distance. A further alternative, or a supplement, is to deactivate the traffic calming device at appointed hours and then let different traffic calming devices be raised or lowered depending on the hour.

An alternative of deactivating the traffic calming devices is based on GPS technology or the like. This system can advantageously be used by the emergency service which thus can locate its emergency vehicles and lower all the traffic calming devices along the turnout road of the vehicles. The system can also be used, for example, by buses in regular services where the system continuously registers the location of the bus and lowers traffic calming devices along the route of the bus as the bus approaches an area with traffic calming devices.

A signalling device should be arranged in connection with the traffic calming device, said signalling device

being adapted to visually indicate when the traffic calming device is out of operation. This can take place, for example, using a light with a certain colour to inform a driver that the traffic calming device will not be low- ered although the vehicle of the driver is authorised to pass the traffic calming device in its lowered position, and he can thus prepare himself for the traffic calming device in an appropriate manner.

An alternative solution in connection with the pass- ing of heavy vehicles, such as heavy trucks and buses, that are not capable of deactivating (that is lowering) the traffic calming device is that the device is lowered when a vehicle with a certain weight approaches or passes. This is achieved by installing sensors, either in one of the ramps 4, 5 or just in front of the traffic calming device, which detect the weight of the vehicle and, if the weight exceeds a certain value, the traffic calming device is deactivated. The purpose of this function is, inter alia, to reduce wear on the traffic calm- ing device and unnecessary strain on the driver. However, it is important for the traffic calming device not to be lowered too quickly so that the function is misused. The optimal situation is if the traffic calming device is flush with the road surface just as the front tyres of the truck reach the front ramp 4 of the traffic calming device and remains flush with the road surface until the truck has completely passed the traffic calming device. Deactivation should take place at such a speed that if the heavy vehicle keeps too high a speed, the vehicle should be affected, but if the speed is the maximum speed or slower, the traffic calming device should not affect the vehicle. Different types of sensors can be used to determine whether a vehicle has completely passed a traffic calming device or not. Fig. 3 is a detailed view of a portion of the traffic calming device in its raised position. In the lowered position, the ramp part 4 is in direct contact

with the vertical part βc of the seal β. While raising the traffic calming device, its circumference becomes greater, in which case the ramp part 4 is removed from the vertical part 6c of the seal 6. The vertical part 6c is attached to the side of the upper part 3 by an adhesive or some fastening means, and the side 6a of the seal 6 which abuts against the upper side of the upper part 3 is also attached to the upper part 3 by an adhesive or some fastening means. This part of the seal is also pressed against the upper part 3 by the coating 12 thereof. The seal 6 is preferably made of rubber or some other similar flexible material which follows the inclination of the ramp part 4. It is advantageous if the ramp part 4 in its upper part 4a is freely movable in the space formed between the seal 6 and the support 14 on which the ramp part 4 mainly rests with the traffic calming device in its raised position. The upper side of the support 14 preferably has an inclination which corresponds to the inclination of the ramp part 4 with the traffic calming device in its raised position. The sealing part 6b that overlaps the ramp part 4 is not attached to the same but only abuts against the upper part 4a of the ramp part and flexibly follows the movement of the ramp part. The sealing part 6b that overlaps the ramp part 4 could enclose the upper part 4a of the ramp part also on the underside, that is a sealing part corresponding to the sealing part 6b could be attached to the lower part of the vertical part 6c of the seal 6 and from there extend along the upper side of the support 14. The coating 12 on the ramp parts 4 and 5 extends preferably from the lower seal 16 all the way to, or just in front of, the upper seal 6 with the traffic calming device in the lowered position, which means that in this embodiment there will be a gap between the coating 12 of the ramp parts 4, 5 and the seal 6 with the traffic calming device in the raised position .

The sealing part βb abutting against, and overlapping, the upper part 4a, 5a of a ramp part 4,5 may also consist of an expandable elastic material and be attached to the upper part 4a, 5a of the corresponding ramp part 4, 5. This means that the sealing part 6b is stretched when the traffic calming device is being raised and when it is in its raised position, and that the sealing part 6b is compressed or is in its normal position when the traffic calming device is in its lowered position. In this embodiment, the coating 12 on the ramp parts 4 and 5 can extend all the way from the lower seal 16 to the upper seal 6.

Fig. 4 is a detailed view of the transition between the road surface and the lower part 5b of a ramp part 5. The ramp part 5 is in its lower part 5b pivotally mounted on a ramp bearing 15. A lower seal 16 ensures that no matter reaches the movable parts.

The advantages of arranging the upper parts 4a, 5a of the ramp parts 4, 5 to be freely movable are many. If the upper part 3 is used as a pedestrian crossing, the particles that are supplied by pedestrians etc to the traffic calming device will practically exclusively land on the upper part since people will walk on the horizontal part of the traffic calming device, and therefore there is no risk of the particles reaching the movable parts since the upper part moves merely vertically and the seal 6 prevents any matter from entering via the upper part 3. In particular, the seal 6 also implies that the risk of pedestrians, animals or devices getting stuck between the ramp parts and the upper part is minimised. Particles, gravel and the like emitted by the vehicles and also rain water, salt etc and other dirt landing on the ramp parts 4, 5 will, owing to the inclination of the latter, run off from the traffic calming device and, thus, further prevent any matter from penetrating the seals 6. When the traffic calming device is lowered and the ramp parts 4,5 are again pressed against the vertical

sealing part βc, they will not entrain any large amounts of dirt etc, but the dirt will be stopped by the part 6b of the seals that overlaps the ramp parts 4, 5 and run off due to the inclination of the ramp parts . The traffic calming device according to the figures has ramps only on its front and rear side seen in the travelling direction, but it may also have ramps on all sides in order to minimise the risk of pedestrians etc. being squeezed.

An alternative embodiment of the invention is illus- trated in Fig. 5. This embodiment substantially corresponds, except in the parts that will be indicated below, to the above described embodiment, for example regarding the nature of the system, coating, seals, technique for deactivating the traffic calming device, managing passing heavy vehicles etc. In this embodiment, the movement is also controlled by an actuator 7, which in this embodiment is pneumatic. A number of pneumatic pistons or bellows are mounted between the stationary lower frame 2 and the movable upper frame 1. These pistons or bellows can be filled with air to perform an upward movement, in which the movable frame 1, the upper part 3 which is mounted on the movable frame 1, and the two ramp parts 4, 5, the upper parts of which are articulated to the upper part 3, constitute the function of a normal traffic calming device. Like in the previous embodiment, this is the normal position of the system. The ramp parts 4, 5 are in this embodiment pivotally arranged in their lower parts 4b, 5b. When evacuating the actuators 7, that is the pneumatic pistons or bellows, all parts 3, 4, 5 are lowered and then constitute a flat road surface.

In this embodiment, a stationary lower frame 2 is provided, which is wholly or partially positioned inside the movable outer frame 1. Between the frames there is a bearing in the form of a number of rolls or wheels 22, of, for example, steel, rubber or plastic. These wheels or rolls 22 are mounted in bearings in the stationary inner frame 2.

The nature and function of the invention will be evident from that stated above and illustrated in the drawings, and of course the invention is not limited to that described above and shown in the accompanying dra- wings. Modifications are conceivable, especially regarding the nature of the various parts, or by using an equivalent technology, without departing from the scope of protection of the invention as defined in the claims,