WO2005050587A1

WO2005050587A1 - Object monitoring method and apparatus

Info

Publication number: WO2005050587A1
Application number: PCT/AU2004/001613
Authority: WO
Inventors: Garry Bowditch; Tom Donnelly; Andrew Luscombe
Original assignee: Tenix Solutions Pty Ltd
Priority date: 2003-11-21
Filing date: 2004-11-19
Publication date: 2005-06-02

Abstract

A method and apparatus for monitoring a moving vehicle, the method including determining a first value of a parameter of the object, comparing the first value with a first test value indicative of unacceptable values of the first value, providing a warning signal to the vehicle if the first value is determined to violate the first test value, then determining a second value of the parameter of the object, comparing the second value with a second test value indicative of unacceptable values of the second value, and collecting information related to the object if the second value violates the second test value.

Description

OBJECT MONITORING METHOD AND APPARATUS

FIELD OF THE INVENTION The present invention relates to a method and apparatus for monitoring and controlling moving objects, of particular but by no means exclusive application with transit systems, such as in monitoring the motion of motor vehicles. In one embodiment, the invention provides a roadside sensor system for adaptively controlling the speed of motor vehicles.

BACKGROUND OF THE INVENTION

A variety of sensors exist for measuring the speed of vehicles remotely, as those vehicles pass a point along the road. These are used both for traffic management and law enforcement, both of which require that traffic be monitored on public roads for breaches of speed limits. In addition, such existing systems are used to gather accurate information about traffic flow, such as for planning road construction, scheduling traffic signals, managing the deployment of law-enforcement resources and enforcing the law.

Typically, existing sensors of this type require the installation of pressure-sensing strips and/or inductive wire loops in the road surface. Others, however, emit a beam of light or electromagnetic radiation towards motor vehicles, and determine speed on the basis of returned signals. Some devices are more suitable for particular applications. For example, law-enforcement applications require measurement systems with a high degree of confidence in the measured speed. In some applications, portability is a desired characteristic; in others, a long and continuous operation is of prime concern.

Thus, although system requirements depend on application, existing sensor systems used in conjunction with control systems generally aim to provide, inter alia , at least some of the following a) highly reliable results; b) appropriate positioning of the vehicle within a photograph (i.e. the number plate well within the camera's field of view); c) continuous, extended unmanned operation; d) road safety benefits on all road surfaces and in all conditions; and e) monitoring of the full range of vehicles likely to be encountered, including motorbikes and trucks.

Many systems in current use do not provide all of these characteristics. Some existing systems cannot be installed on certain types of road surfaces, others cannot effectively process long vehicles while others are not always triggered by very light vehicles, such as motor bikes .

SUMMARY OF THE INVENTION

The present invention provides, therefore, a method of monitoring a moving object such as a vehicle, comprising: determining a first value of a parameter of said object; comparing said first value with a first test value indicative of unacceptable values of said first value; providing a warning signal to said object if said first value is determined to violate said first test value; then determining a second value of said parameter of said object; comparing said second value with a second test value indicative of unacceptable values of said second value; and collecting information related to said object if said second value violates said second test value. Preferably said collecting of information comprises photographing said object.

In one embodiment, the method includes collecting the information related to said object only if said first value violates said first test value and said second value violates said second test value.

The parameter may comprise any one of: speed, identification, location and direction of the object. Thus, the method essentially responds to unacceptable speeds, identities, locations or directions.

Any other desired parameter may be used. For example, in other embodiments, where the object is a vehicle, the parameter may comprise weight, wheel diameter, axle count, floor height or roof height. Such parameters allow different types of vehicles to be identified, so that the warning signal can be tailored to the type of vehicle, if appropriate. Thus, such parameters would typically be measured together with the measurement of speed, but could be employed alone. For example, a different unacceptable value of speed (in the form of a maximum acceptable speed) may be assigned to particularly high vehicles (hence likely to have a high centre of gravity) approaching a tight bend; vehicles with three or more axles may be deemed to be trucks and required to travel more slowly than other vehicles when approaching a school crossing or stop lights. Generally, trucks may be required to slow down more or earlier than sedans, and it may be appropriate to warn them and possibly take their pictures at slower speeds. Loaded trucks (identified by weight, height or both) may require a different warning to unloaded ones.

Indeed, thresholds in general can if desired be calculated by a control system, rather than pre-set. For example, when the parameter is speed, the first and second test values could be set such that a warning signal is issued to the fastest 3% of all vehicles, rather than vehicles driving above a particular speed, on the basis that it is the drivers at extreme speeds that require a warning. Statistics can be calculated and the speed that 3% of drivers drove faster than on one day can be used as the threshold for the next day.

A slightly more complicated threshold calculation method comprises determining the speed 10 kirt/h greater than the speed of the median driver, and using that speed as the first and second test values. Again, the typical driver is used as an indicator of what is safe, and deviations from this by more than 10 km/h are deemed unacceptable. The advantage of using a fixed offset from the median speed is that all drivers can avoid receiving a warning (whereas without an offset the fastest 3% of drivers will always receive a warning even if under the speed limit and driving safely) .

The method may include determining a first value of each of a plurality of parameters of said object, or determining a second value of each of a plurality of parameters of said object, or determining a first value of each of a plurality of parameters of said object and determining a second value of each of a plurality of parameters of said object.

In one particular embodiment, said parameter is speed and said first and second test values are maximum allowable speeds .

In some embodiments, said first and second test values are identical . The warning signal may comprise an optical signal (such as a flashing light or lights, or a variable message sign, or both) , but may comprise an audible signal, including - for example - a signal transmitted by radio transmission.

The method may include measuring one or more environmental, traffic or road conditions, and selecting or generating the first test value, the second test value or the warning signal accordingly.

It is envisaged that this would be facilitated by employing a suitable monitoring device or devices, such as a thermometer or precipitation gauge. This would allow warnings to be provided at lower speeds, in more dangerous conditions, or to tailor the warning in, for example, wet conditions, snowy conditions, icy conditions, potentially icy conditions, or heavy traffic conditions.

In one aspect, the invention provides a method for controlling the speeds of moving motor vehicles, according to the method described above.

The present invention also provides an apparatus for monitoring a moving object, comprising: a first detector for measuring a first value of a parameter of said object; a warning device for emitting a warning signal; a second detector for measuring a second value of the parameter of said object; a controller for comparing said first value with a first test value indicative of unacceptable values of said first value and for comparing said second value with a second test value indicative of unacceptable values of said second value; and a monitor for monitoring said object; wherein the warning device is adapted to emit the warning signal if the first value is determined by the computing means to be unacceptable, and the controller is operable to control the monitor to collect the information related to said object if said second value violates said second test value.

In one embodiment, the controller is operable to control the monitor to collect the information only if said first value violates said first test value and said second value violates said second test value.

The controller typically comprises a computer or other electronic computing means.

In one embodiment, the monitor comprises a camera for photographing said object.

The present invention also provides an apparatus for monitoring a moving object, comprising: a speed measurement array comprising of one or more speed measurement devices for measuring a speed of said object; a warning device for emitting a warning signal; a monitoring array of one or more monitoring devices for monitoring said object and including at least one camera for photographing said object; and a control system in data communication with said array of speed measurement devices, with said warning device and with said array of monitoring devices, and for controlling said warning devices, said control system including computation means for (a) receiving at least one output from said speed measurement array indicative of said speed of said object, (b) comparing said speed with a first threshold speed, (c) activating said warning device if said speed exceeds said first threshold speed, (d) receiving at least one output from said monitoring array indicative of said speed of said object, (e) comparing said speed with a second threshold speed, (f) activating said camera to photograph said object if said speed exceeds said second threshold speed.

The monitoring array may include a signal processor for processing said output signal before outputting said output signal .

The computation means may also be operable to determine further information from said outputs, such as other parameters of interest which may be modified based on inputs from external devices .

The apparatus may include a plurality of said warning devices. The apparatus may include a plurality of said monitoring devices.

Each of the monitoring devices may be a composite device comprising multiple detectors. Each of the warning devices may be a composite device comprising multiple arrangements of warning devices .

Alternatively, said monitoring device may comprise a plurality of photodetectors each having a known detection direction, wherein the direction of a reflection event is determinable from said known detection directions.

Preferably said each of said monitoring devices has a detection region that is relatively broad in a first plane and relatively narrow in a second plane perpendicular to said first plane. Preferably said first plane is substantially upright.

Preferably said each of said warning devices has a region of influence that is relatively broad in a first plane and relatively broad in a second plane perpendicular to said first plane. Preferably said first plane is substantially upright . Preferably said monitoring device uses flush mounted road surface devices. In other embodiments, however, said monitoring device may be mounted away from the road surface.

Preferably said apparatus includes at least two monitoring devices .

Preferably said apparatus includes a manual override function using inputs to said control unit.

Preferably said apparatus is able to compute revised parameters based on external real time information.

In one aspect, the invention provides an apparatus for controlling the speed of moving motor vehicles, including the apparatus described above.

BRIEF DESCRIPTION OF THE DRAWINGS

In order that the present invention may be more clearly ascertained, embodiments will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a general schematic view of a safety system according to the present invention with a typical field of view thereof, viewed from above; Figure 2 is a schematic view of a single safety treatment of a safety system according to another embodiment (comparable to a single safety treatment of the embodiment of figure 1) ; Figure 3A is a schematic view of a first portion of a sensor system of the safety system of figure 2, viewed from above; Figure 3B is a schematic view of a second portion of the sensor system of the safety system of figure 2, viewed from above; Figure 4A is a schematic view of a first portion of a first alternative sensor system of the safety system of figure 2, viewed from above; Figure 4B is a schematic view of a second portion of the first alternative sensor system of the safety system of figure 2, viewed from above; Figure 5A is a schematic view of a first portion of a second alternative sensor system of the safety system of figure 2, viewed from above; Figure 5B is a schematic view of a second portion of the second alternative sensor system of the safety system of figure 2, viewed from above; Figure 6A is a schematic view of a first portion of a third alternative sensor system of the safety system of figure 2, viewed from above; Figure 6B is a schematic view of a second portion of the third alternative sensor system of the safety system of figure 2, viewed from above; Figure 7A is a schematic view of an alternative arrangement of flashing lights of the warning zone of figure 3A; Figure 7B is a schematic view of another alternative arrangement of flashing lights of the warning zone of figure 3A; and Figure 7C is a schematic view of a still further alternative arrangement of flashing lights of the warning zone of figure 3A.

DETAILED DESCRIPTION A safety system 10 for controlling the speed of motor vehicles according to an embodiment of the present invention is shown schematically in figure 1 installed on a road 12 , as viewed from above .

Road 12 has six lanes (with a median strip 13), but system 10 can be employed with a road of any number of lanes, and with or without a median strip. Broadly, the safety system 10 includes three safety treatments (each of a different type) for controlling and directing traffic flow on the road 12, each type of safety treatment associated with a respective region 14a, 14b,

14c of road 12, respective local controllers 16a, 16b, 16c for collecting data from the safety treatments concerning vehicles in each road region 14a, 14b, 14c, and a control unit 18 for coordinating the operation of the local controllers. It will be appreciated, however, that although three safety treatments of different types are included in system 10, other systems may include any number of safety treatments of identical or different types.

Each type of safety treatment comprises safety components (not shown in figure 1 but described in detail below) according to the particular safety requirements and hazards identified at a specified location. A typical type of safety treatment, according to this embodiment, monitors between 50 metres and 20 km of road surface. As mentioned above, the system 10 includes three safety treatments for monitoring respectively road regions 14a, 14b, 14c which span, respectively, stretches A-B, C-D and E-F of road 12. The distance between road regions provided with a safety treatment (cf . B-C and D-E in figure 1) is not limited but is typically in the range of 100 metres to several kilometres.

Each region 14a, 14b, 14c with a safety treatment is associated with a respective local controller 16a, 16b, 16c; the local controllers 16a, 16b, 16c are themselves controlled by a control unit 18. Control unit 18 downloads information based upon measured parameters and external information so that warning information (explained in greater detail below) can be provided appropriate to the conditions . The information collected by the control unit 18 allows the road safety and traffic flow benefits to be conferred on a network of road infrastructure. Information can also be provided to motorists for route optimization purposes.

Each safety treatment includes a sensor system for detecting one or more desired parameters of vehicles in the respective road region 14a, 14b, 14c; the control unit 18 comprises a computer (or other digital computing device) for receiving data from each of the three sensor systems and performing the required analysis to determine vehicle speed as well as other parameters of interest. The analysis phase is also discussed in further detail below.

Figure 2 is a plan view of a typical installation of a single safety treatment (such as that associated with road region 14a of figure 1) according to an embodiment of the present invention, and includes - as discussed above - a sensor system (not shown) . The safety treatment is deployed in association with a school crossing 20 for school children, and is for controlling the speed of vehicles as they approach the school crossing. It should be noted, however, that any number of associated safety treatments can be provided, along the lines illustrated in figure 1. It will be noted that the road region monitored by the safety system comprise a plurality of separated zones on each side of the road (i.e. associated with first and second directions of traffic flow 22a, 22b) . School crossing 20 extends from Gi-Hx in first direction of traffic flow 22a, and from G₂-H₂ in second direction of traffic flow 22b.

In each direction of traffic flow 22a, 22b, the safety treatment employs four zones . In each direction of traffic flow 22a, 22b, a vehicle would encounter successively: a signal area, a speed measurement zone, a warning zone (all before the school crossing 20) and a monitor zone (after the school crossing 20) . Thus, in the first direction of traffic flow 22a, the zones are (as one approaches the school crossing 20) signal zone 24a extending from Ai-Bi, speed measurement zone 26a extending from Cx-Di and warning zone 28a extending from Ei-Fi; after the school crossing 20 there is monitor zone 30a extending from Jι~Kι.

The distance Aι-Gχ (i.e. from the beginning of the signal zone 24a to the beginning of the school crossing 20) is in this embodiment of the order of 200 metres. This allows drivers sufficient time to take heed of warnings provided in the signal zone 24a.

In the second direction of traffic flow 22b, the zones are (as one approaches the school crossing 20) signal zone 24b extending from A₂-B₂, speed measurement zone 26b extending from C₂-D₂ and warning zone 28b extending from E₂-F₂; after the school crossing 20 there is monitor zone 30b extending rom J₂-K .

The sensor system of the safety treatment in first direction of traffic flow 22a of figure 2 is shown schematically in figures 3A and 3B, as viewed from above. That of second direction of traffic flow 22b (which is identical) has been omitted for clarity.

This sensor system also corresponds to any one of the three safety treatments illustrated in figure 1.

Figure 3A is a view of only that portion of road 19 that includes the speed measurement zone 26a and warning zone 28a. Signal zone 24a has been omitted, as it includes no active components, but rather simply signage or traffic signals to warn drivers of the proximity of a school crossing. Figure 3B is a view of that portion of road 19 that includes the school crossing 20 and subsequently the monitor zone 30a.

Speed measurement zone 26a is provided with four speed measurement devices 32a, 32b, 32c, 32d located at or near respective corners of the speed measurement zone 26a so as to be able to determine the speed of vehicles in the speed measurement zone. Each speed measurement device 32a, 32b, 32c, 32d comprises an in-road infra-red sensor and detector for determining the speed of vehicles in the speed measurement zone .

In other embodiments (examples of which are described below) , other speed measurement devices may be preferred as will be appreciated by those in the art. In each embodiment, the determination of speed is performed by any suitable existing technique, but typically this comprises performing time-of-flight or doppler shift analyses of infra-red signals reflected from vehicles in the speed measurement zone .

Speed determinations can be made by the speed measurement devices themselves but, alternatively, such calculations can be made by the local controller of this safety treatment (not shown, but cf. local controller 16a of figure 1) , with which the speed measurement devices are in data communication. In either case, the speeds of vehicles within speed measurement zone 26a are ultimately available to that local controller.

Thus, by means of speed measurement devices 32a, 32b, 32c, 32d, the speed of each vehicle is measured as it passes through speed measurement zone 26a, extending (as described above) from Ci to Di. (A similar determination is performed for vehicles in speed measurement zone 26b, extending from C₂ to D₂. ) Warning zone 28a is provided with a number (in this embodiment, seven) of unidirectional flashing lights 34. These lights are located along the centre of the traffic lane, and oriented to be visible to an approaching driver only. The use of multiple lights allows for error correction and consistency checking and also provides very high reliability, which is important in safety critical applications such as with a school crossing.

The colour of the light emitted by lights 34 is in accordance with local regulations but will typically be orange or as otherwise prescribed for warning lights. The number of lights can varied as desired, but is expected to be desirably between 5 and 50 in many applications and will largely depend on the local speed limit.

The separation distance between the lights is typically 2 metres .

The lights 34 and the speed measurement devices 32a, 32b, 32c and 32d are all coupled to the local controller of this safety treatment.

Thus, the local controller is programmed to compare vehicle speeds detected in speed measurement zone 26a with a first threshold speed and, if a detected vehicle speed exceeds that threshold speed, to respond by activating lights 34 to flash and the variable message sign 35 to display a message, and hence warn the driver of the speeding vehicle that he or she is speeding. The threshold speed may be a local speed limit or the maximum speed deemed safe in close proximity to a school crossing.

The lights 34 and variable message sign 35 can also be controlled by the local controller to activate in a particular manner according to the level of excess speed. For example, this can be effected by varying the number of lights flashed, or the frequency of the flashing, or both. Thus, the number of lights flashed and the frequency of the flashing would generally be increased with the degree of excess speed and hence the severity of the warning required. Also, messages with varying degrees of forcefulness can be displayed on the variable message sign depending on the severity of the warning required.

In some embodiments, the combination of lights in the road (to gain attention) together with one or more variable message signs (to provide written and other symbolic information) provides particularly effective warnings.

Referring to figure 3B, monitor zone 30a is provided with a second set of speed measurement devices 36a, 36b, 36c, 36d, which are comparable to speed measurement devices 32a, 32b, 32c, 32d and also in data communication with the local controller. Monitor zone 30a is also provided, further along the road in the traffic direction 22a, with a pair of cameras 38a, 38b for photographing speeding vehicles. The cameras are located - in this embodiment - embedded in the road surface. Alternatively, the cameras may be located off-road (such as mounted on posts or gantries beside or above the road) , as - in some applications - these permit better images to be collected and can be easier to maintain.

The cameras 38a, 38b are also in data communication with the local controller.

The speed measurement devices 36a, 36b, 36c, 36d and cameras 38a, 38b in monitor zone 30a are adapted and located to measure and photograph all classes of vehicles with high reliability.

Vehicle speeds determined from this monitor zone 30a by one or more speed measurement devices are compared by the local controller with a second threshold speed, which may be - but is not necessarily - the same as the first threshold speed. If an excess speed is detected, the local controller activates cameras 38a, 38b so that a photographic record of the incident and hence of the speeding vehicle is obtained.

To use the safety system of either embodiment described above in roadside speed calculations, the sensor systems are preferably controlled and monitored in the area of the roadway.

If a number of speeds are calculated from different physical devices (such as speed measurement devices 32a,

32b, 32c, 32d) , the speeds can be checked for consistency. If the speeds are consistent, there can be a high degree of confidence that there was no interference, and the respective vehicle did indeed travel at constant speed and direction.

As mentioned above, in other embodiments speed measurement devices 32a-32d and 36a-36d may be replaced by other types of speed measurement devices; in some cases these may be placed in use in different locations from those of devices

32a-32d and 36a-36d. In one alternative embodiment, for example, the speed measurement devices can be in the form of piezoelectric sensor strips 40a and 40b (sensitive to the weight of passing vehicles) , as shown in figures 4A, and piezoelectric sensor strips 40c and 40d as shown in figure 4B.

However, in some circumstances it may not be desired to embed the sensors in the road (such as if it is not desirable to cut into the road) . Referring to figures 5A and 5B, in one such embodiment, instead of speed measurement devices 32a-32d and 36a-36d, the sensor system includes speed measurement devices 42 and 46. Each is adapted to be located on a post (not shown) beside road 19. Each comprises light-emitting and light-sensing elements; the light-emitting elements are arranged to emit light beams into the traffic flow so as to be reflected from the rear surfaces of passing vehicles (generally in directions 44 and 48 respectively) . Reflections from a vehicle are then detected by the light-sensing elements. Vehicle speed is then determined by the timing of the detection of reflected light and the known geometry of the light beams.

Referring to figures 6A and 6B, in an alternative embodiment speed measurement devices 42 and 46 are replaced by speed measurement devices 52 and 56 located on respective gantries 60 and 62 above the path of vehicles on road 19. Speed measurement devices 52 and 56 each emit a pair of beams downwardly, and allow speed to be determined by time of flight calculation (to determine when a vehicle is present) combined with the timing of the respective interruption of each beam.

As also mentioned above, warning zone 28a is provided with a number of unidirectional flashing lights 34 located along the centre of the traffic lane, and oriented to be visible to an approaching driver only. However, in other embodiments different patterns of lights may be employed, such as in one or more lines across the lane (see lights 64 of figure 7A) , a pair of lines of lights along the edges of the lane (see lights 66a and 66b of figure 7B) , or a few flashing lights in the lane (such as lights 68 of figure 7C) . Such arrangements might be employed if it were feared that the configuration of figure 3A could confuse drivers, perhaps by suggesting lane demarcation.

In some embodiments, other parameters may be measured. For example, in other embodiments, the parameter may comprise one or more of vehicle identification, location, direction, weight, wheel diameter, axle count, floor height or roof height. Such parameters allow different types of vehicles to be identified, so that the warning signal can be tailored to the type of vehicle, if appropriate. For example, a different unacceptable value of speed (in the form of a maximum acceptable speed) may be assigned to particularly high vehicles (hence likely to have a high centre of gravity) approaching a tight bend; vehicles with three or more axles may be deemed to be trucks and required to travel more slowly than other vehicles when approaching a school crossing or stop lights. Generally, trucks may be required to slow down more or earlier than sedans, and it may be appropriate to warn them and possibly take their pictures at slower speeds. Loaded trucks (identified by weight, height or both) may require a different warning to unloaded ones.

Thus, in such embodiments, the first threshold speed, the second threshold speed, or both, can be selected or generated (by calculation, for example) according to the first and/or second measured value of the parameter. Similarly, the warning signal can be selected or generated according to the first and/or second measured value of the parameter. In such embodiments, the computer of control unit 18 is programmed to identify or categorize the vehicle on the basis of the measured values of the parameter or parameters, and to select or generate the threshold speed, the speed thresholds and/or the warning signal accordingly.

Modifications within the spirit and scope of the invention may be readily effected by those skilled in the art. For example, although the word light has been used above with the technical meaning as commonly used in the fields of physics and engineering (that is, visible light) , the invention may also be implemented with other forms of electromagnetic radiation such as infrared and ultraviolet light. Therefore, in particular implementations of the sensor system, the light-emitting elements may emit infrared or ultraviolet light and the light-sensing elements may sense infrared or ultraviolet light. It is to be understood, therefore, that this invention is not limited to the particular embodiments described by way of example hereinabove.

In the preceding description of the invention, except where the context requires otherwise owing to express language or necessary implication, the word "comprise" or variations such as "comprises" or "comprising" is used in an inclusive sense, i.e. to specify the presence of the stated features but not to preclude the presence or addition of further features in various embodiments of the invention.

Further, any reference herein to prior art is not intended to imply that such prior art forms or formed a part of the common general knowledge .

Claims

THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS:

1. A method of monitoring a moving object, comprising: determining a first value of a parameter of said object; comparing said first value with a first test value indicative of unacceptable values of said first value; providing a warning signal to said object if said first value is determined to violate said first test value; then determining a second value of said parameter of said object; comparing said second value with a second test value indicative of unacceptable values of said second value; and collecting information related to said object if said second value violates said second test value.

2. A method as claimed in claim 1, wherein said collecting of information comprises photographing said object.

3. A method as claimed in claim 1, wherein the parameter comprises any one of: speed, identification, location and direction of the object.

4. A method as claimed in claim 1, wherein the parameter comprises any one of: weight, wheel diameter, axle count, floor height and roof height.

5. A method as claimed in claim 1, including selecting or generating the first test value according to the first value of said parameter, the second value of said parameter or both the first and second values of said parameter.

6. A method as claimed in claim 1, including selecting or generating the second test value according to the first value of said parameter, according to the second value of said parameter or according to both the first and second values of said parameter.

7. A method as claimed in claim 1, including selecting or generating the warning signal according to the first value of said parameter, according to the second value of said parameter or according to both the first and second values of said parameter.

8. A method as claimed in claim 1, further including determining a first value of each of a plurality of parameters of said object.

9. A method as claimed in claim 1, further including determining a second value of each of a plurality of parameters of said object.

10. A method as claimed in claim 1, further including determining a first value of each of a plurality of parameters of said object and determining a second value of each of a plurality of parameters of said object.

11. A method as claimed in claim 1, wherein said parameter is speed and said first and second test values are maximum allowable speeds.

12. A method as claimed in claim 1, including measuring one or more environmental, traffic or road conditions, and selecting or generating the first test value, the second test value or the warning signal accordingly.

13. A method as claimed in claim 1, wherein said first and second test values are identical.

14. A method as claimed in claim 1, wherein the warning signal comprises an optical signal.

15. A method as claimed in claim 14, wherein the optical signal comprises lights embedded in the road.

16. A method as claimed in claim 14, wherein the optical signal comprises a variable message sign.

17. A method as claimed in claim 14, wherein the optical signal comprises a combination of lights in the road and a one or more variable message signs.

18. A method as claimed in claim 1, wherein the warning signal comprises an audible signal.

19. A method as claimed in claim 1, wherein said object is one or a plurality of objects and the method includes calculating the first test value, the second test value or both the first and second test values from measured values of the parameter for the plurality of objects.

20. A method as claimed in claim 19, including calculating the mean or median of said measured values of the parameter for the plurality of objects.

21. A method for controlling the speeds of moving motor vehicles, including a method of monitoring a moving object as claimed in claim 1.

22. An apparatus for monitoring a moving object, comprising: a first detector for measuring a first value of a parameter of said object; a warning device for emitting a warning signal; a second detector for measuring a second value of the parameter of said object; a controller for comparing said first value with a first test value indicative of unacceptable values of said first value and for comparing said second value with a second test value indicative of unacceptable values of said second value; and a monitor for monitoring said object; wherein the warning device is adapted to emit the warning signal if the first value is determined by the computing means to be unacceptable, and the controller is operable to control the monitor to collect the information related to said object if said second value violates said second test value.

23. An apparatus as claimed in claim 22, wherein the controller is operable to control the monitor to collect the information only if said first value violates said first test value and said second value violates said second test value.

24. An apparatus for monitoring a moving object, comprising: a speed measurement array comprising of one or more speed measurement devices for measuring a speed of said object; a warning device for emitting a warning signal; a monitoring array of one or more monitoring devices for monitoring said object and including at least one camera for photographing said object; and a control system in data communication with said array of speed measurement devices, with said warning device and with said array monitoring devices, and for controlling said warning devices, said control system including computation means for (a) receiving at least one output from said speed measurement array indicative of said speed of said object, (b) comparing said speed with a first speed threshold, (c) activating said warning device if said speed exceeds said first threshold, (d) receiving at least one output from said monitoring array indicative of said speed of said object, (e) comparing said speed with a second speed threshold, (f) activating said camera to photograph said object if said speed exceeds said second threshold.

25. An apparatus as claimed in claim 24, wherein the monitoring array includes a signal processor for processing said output signal before outputting said output signal.

26. An apparatus as claimed in claim 24, wherein the computation means is operable to determine further information from said outputs .

27. An apparatus as claimed in claim 24, wherein said apparatus includes a plurality of said warning devices.

28. An apparatus as claimed in claim 27, wherein each of said warning devices is a composite device comprising multiple arrangements of warning devices.

29. An apparatus as claimed in claim 28, wherein the composite warning device comprises lights in the road and one or more variable message signs.

30. An apparatus as claimed in claim 24, wherein said apparatus includes a plurality of said monitoring devices.

31. An apparatus as claimed in claim 30, wherein each of said monitoring devices is a composite device comprising multiple detectors.

32. An apparatus as claimed in claim 24, wherein said monitoring device comprises a plurality of photodetectors each having a known detection direction, wherein the direction of a reflection event is determinable from said known detection directions.

33. An apparatus as claimed in claim 30, wherein each of said monitoring devices has a detection region that is relatively broad in a first plane and relatively narrow in a second plane perpendicular to said first plane.

34. An apparatus as claimed in claim 33, wherein said first plane is substantially upright.

35. An apparatus as claimed in claim 28, wherein each of said warning devices has a region of influence that is relatively broad in a first plane and relatively broad in a second plane perpendicular to said first plane.

36. An apparatus as claimed in claim 35, wherein said first plane is substantially upright.

37. An apparatus as claimed in claim 24, wherein said monitoring device uses flush mounted road surface devices

38. An apparatus as claimed in claim 24, wherein said monitoring device is mounted away from a road surface.

39. An apparatus as claimed in claim 24, including a manual override function using inputs to said control unit.

40. An apparatus as claimed in claim 24, wherein said computation means is operable to compute revised parameters based on external real time information.

41. An apparatus for controlling the speed of moving motor vehicles, including an apparatus for monitoring a moving object as claimed in claim 24.