e-Toll Gantries: How they work

genetic said:
The e-tolls don't use simple technology. They are quite sophisticated. They don't take pictures, they take continuous hi-res video and use sophisticated software to decipher car type / OCR from numberplates etc. I'm sure they designed the gantries with rain in mind. ;)
Click to expand...

I know they aren't, I worked in the ANPR arena. And I KNOW they don't work well in rain (rain = white noise which is very difficult to remove out of video/images). And those cameras wont be high res AND high frame rate cameras. I few years ago the very expensive cameras ran 5mp at 30fps and you had to pay for the API in order to get those framerates. Tech has advanced with respect to sensors. Deciphering car type/class (seeing as you know all physical attributes of the gantry) and OCR isn't rocket science, the rocket science lies in making the system immune against variances (ie light (day night), rain , reflections etc etc).

Very good recognition rates are typically around 94% (As is the case at ACSA), if you want 97% the costs went up significantly and 100% was near impossible or the costs unjustifiably high. At 2million cars it means appr 100k will be missed in the system which translates into big money.
 
Last edited:
A bucket of mud should do the trick , half on the front number plate and half on the back number plate .
 
b_crazy said:
What's stopping Sanral from forcing newly registered cars to buy e-tags, as part of new vehicle registration?

The next obvious question is how long before people are forced to buy e-tags at their car's next license renewal?
Click to expand...

creeper said:
To my understanding, they will need to changethe RTA and Etoll act to do this. Remember. Etag buy is not mandatory
Click to expand...

So how long do you guys think it will be before your number plate comes with a chip in it?
 
Arctus said:
So how long do you guys think it will be before your number plate comes with a chip in it?
Click to expand...

It doesn't really matter. If people still refuse to pay, the system will be unsustainable. E-tagged, chipped or not.
 
Lukcydog said:
I used to work in this field so I can give a basic idea. The tag is based on RFID technology, so in theory when you drive through the gate, the RFID is triggered to pulse its information to the gantry. This is the easy solution for e-tolling.

You will see that there are the black lights and cameras posted next to each other. The white area of a car's number plate is designed/painted to reflect black light which are then picked up by the cameras as a black and white image. You will also see that there are paint markings on the road under the gantry that are used as trigger points. The trigger points initiate the taking of pictures as well as determining the class of vehicle currently passing the gantry. They then have a server/s that process the images to retrieve the number plate, length of vehicle. They also take a picture of the vehicle as part of the record in case of a dispute from clients. The problem with number plate recognition is the fact that typical accuracy is 94% (to reach 98% accuracy starts costing so much its not feasible), which leaves a massive margin of undetectable plates. So if a plate can't be recognised automatically, they have to manually annotate the "toll" which will be at cost to them. I don't know what camera's they are using but we used to use ARHungary's product (currently running at ACSA aiports when you go into the parking area where you pull your ticket) which is incredibly fast, very accurate, but very very expensive. The one used for e-toll look like a cheaper solution. So SANRAL want you to use tags, because it makes they life very very easy in terms of maintenance and effort.

I hope someone finds this interesting.
Click to expand...

The cameras are all IR, not UV. The black lens is an IR filter.
There's 3 photos per "transaction" and they use a radar based system to determine vehicle volume.
The ANPR software is running on servers in the gantry and is pretty accurate, as provided by the camera manufacturers, PIPS http://www.pipstechnology.co.uk/
 
IR hey... so then we just need to install IR Leds around our numberplates
 
From what I've read you're going to need some seriously powerful IR LEDs and they'll likely have to be pointed directly at the cameras to have any effect.

I know for a fact that there's PIPS cameras in the mobile policing vehicles, mounted front and rear of those Ford Everests. And the cameras mounted on the gantries look identical. I haven't seen them close up though
 
BrentT said:
what about a clear film that blocks IR...anything in mind?
Click to expand...

I think the idea is to reflect the IR on the whole number plate then the cameras IR will get a solid IR reflection and no definition , may be that will work.

Necro thread BTW.
 
genetic said:
Does not work.
Click to expand...

Actually, it does work.

There's a company that makes one, and I've been testing it out on my car for over a year. So far the results are a mixed bag of invisible plates under most circumstances and partially visible plates in others.

The only catch is that it only works on perspex number plates.
 
Whipme said:
There's a company that makes one, and I've been testing it out on my car for over a year. So far the results are a mixed bag of invisible plates under most circumstances and partially visible plates in others.
Click to expand...

Testing it how? With gantry cameras?
 
You must log in or register to reply here.
Back
Top
Sign up to the MyBroadband newsletter
X