A unique combined weight and speed enforcement system will go live on Tower Bridge on 29th April 2004 to replace existing measures to help protect its unique structure. This system is the first of its kind in the UK.
Speed Check Services developed the system for The Corporation of London, owners of the 110-year old bridge, with funding from Transport for London to help protect the structural integrity of the bridge, which forms the eastern boundary of the Congestion Charging zone. The system replaces existing measures to ensure that weight and speed limits are adhered to; they have been clearly signed on each approach to the bridge.
The system works by using SPECS cameras located on each approach to the bridge. The weight enforcement system consists of special loops set into the road surface on each approach to the bridge. The loops detect goods vehicles with a potential weight of 18 tonnes - the maximum weight limit. This will prohibit goods vehicles with more than two axles. If a vehicle is over 18 tonnes the image capture system will be triggered to record the vehicle's number plate. The speed system will be constantly monitoring vehicles as they pass over the bridge, calculating the time taken to travel from point A to point B. This time calculation will give the average speed. The speed limit on the bridge is 20mph.
The speed and weight restrictions have been in place since 1955; these have traditionally been enforced by patrolling police officers. The new system will provide a 24/7 deterrent to overweight and speeding vehicles. The City of London Police will be responsible for the management of the system. Number plates of vehicles exceeding the speed and/or weight limit will be checked against DVLA records and penalty charge notices issued.
For further information please contact Geraldine Blackwood at SpeedCheck: [email protected]
'SPECS' is a type of digital speed camera. It is manufactured by Speed Check Services.
The speed trap consists of a pair of cameras. The first camera reads your numberplate and records the time, the second camera further down the road does the same thing, and the system then calculates your average speed between the two cameras.
Sometimes more than two cameras may be used to cover an extended stretch of road, though it is believed they always operate in pairs, not consecutively.
Each camera stores a photo of your vehicle, though this is alledged discarded if you are not exceeding the speed threshold.
The Big Flaw
Neither camera measures your speed directly, so if you turn off the road between the cameras, or turn onto it, or stop between them, they can't catch you exceeding the speed threshold.
This means that if you inadvertently go thru the first one over the limit, all you need to do is slow to below the limit, so that your average speed between the two cameras is below the speed threshold. Of course, working this out in your head is somewhat difficult, so drivers sometimes over-compensate and can be seen crawling towards the second camera. On high speed roads this can create dangerous situations.
Other drivers can be seen driving for miles staring at their speedometer — a stupid and potentially fatal distraction effect.
Birds of Prey
The cameras themselves consist of a fairly standard surveillance camera housing with infra-red illuinators attached to either side. The housings are painted yellow. The poles on which they are mounted are painted dark blue.
Perched on limbs that extend out over the road this gives them a resemblance to a menacing bird waiting for its next victim, earning them the nickname of
I cant believe that only one driver every 5 minutes went over 20mph! Their average must have included the middle of the night - and even then its hard to believe. As has been noted, most people dont even notice the 20mph limit and assume its 30mph, and even then they go faster.
What is really impressive is the way in which detailed records are available of all cars driving over the bridge but no cameras are available to record serious assaults of pedestrians such as happened two weeks ago, when notices were posted asking for witnesses. Surely assaults on the general public are more important than cars driving slighly over the speed limit - or do I have my priorities wrong!
We are continually told we need to keep to the speed limit and that the standard road speed for most of Great Britain is 30MPH going up-to the National Speed limit. If that is the case then most people make 'a reasonable assumption' that 30MPH is the correct speed and that they are good citizens by keeping to this speed limit. When it then comes to somewhere that the speed limit is reduced to 20MPH, the 'good citizen' then makes the assumption that they are driving at a normal and adequate speed, therefore not checking to see if they should reduce there speed further than they already are. Due to this, I feel that greater emphasise should be applied to 20MPH signage so as to reduce fines for what would normally be a 'good citizen'. An example for this would be that 'Harry' goes at 30MPH everywhere, he doesn't need to check as he knows he is always driving at the standard and correct speed, when he sees a road sign his brain makes the correct assumption that he is going the right speed as 70% of the time it is 30MPH and 28% of the time it is even faster, is it therefore Harry's fault that he misses a road sign that suddenly reduces by 10%? Making him out to be a criminal?? Surely this is likely to happen again unless a road signs or warning signals are created that differentiate themselves in a clearer method.
Good points from Alan and Melanie - come the revolution I'd vote for you both! Leading on from Alan's point about selective use of cameras - any time I've asked for copies of CCTV images, somehow those particular cameras happened to be out of action at my specified time ... something I'm sure the prosecution team in the Jean Charles de Menezes case recognise.
When I took my driving test there was a VERY important aspect to the test: being able to READ signs. Just driving along at 30mph in the blind hope that the speed limit is at least 30mph would no doubt result in the examiner uttering that tired phrase "I'm sorry Mr. Blind Driver, but on this occasion you have not met the required standards".
Now, perhaps driving tests have changed over the years, and it is no longer a requirement to be pro-actively aware of the speed limit you are currently driving in... but I doubt it.
On the subject of cameras: those new wizzy cameras can detect and identify cars going over the speed limit simply because cars have registration plates that the cameras can read! Humans are a bit harder to track! (unless of course, we go down the police-state route and embed an RFID chip inside every new-born baby.....)