Number plates

[streaky]

With all teh regulations governing number-plates, can any knowledgeable PHer say whether a number-plate split lengthways down the middle and glued back together such that the outside formed an obtuse (over 90) angle would:

A) Be legal?

B) Reflect a laser beam anywhere other than back to the source?

If A + B = TRUE then "BINGO!" (maybe?)

Streaky

[sqwib]

Why would you want to do this?

If you're trying to confuse an ANPR, they don't use laser.

If your trying to confuse a laser-gun, they don't focus on number plates.

However, if what you are trying to do is make your number plate unreadable, then that is illegal.

Perhaps I don't really understand the question.

[streaky]

sqwib said:

Why would you want to do this? If you're trying to confuse an ANPR, they don't use laser. If your trying to confuse a laser-gun, they don't focus on number plates. However, if what you are trying to do is make your number plate unreadable, then that is illegal. Perhaps I don't really understand the question.

sqwib - the first, and easiest, target for a laser is the number-plate because it's naturally reflective (white ones anyway) and it's flat. That's why the recommended fitting location for radar diffusers is by the numbber plate. Anything that is not illegal and at least buys some time to slow down would be of interest to many PHers (if I read their posts correctly ) - Streaky

[sqwib]

streaky said:

Anything that is not illegal and at least buys some time to slow down would be of interest to many PHers (if I read their posts correctly )

Fair point, but I don't think number plates are as important as you say. Lasers will reflect from any surface. Bikes don't have front plates but can still be 'lasered'.

Time to nail my colours to the mast. I do most of my driving in Mid-Wales and have never been caught for speeding. My view is that talivans, gatso's, laser-guns etc. are a Bad Idea in the majority of cases, but as long as they exist to threaten our licences and wallets, then it's not difficult to keep on the right side of them. Limits are generally well posted and it's only a matter of due care and attention to adjust one's driving to accommodate for them.

I wholeheartedly support those who campaign to have them abolished, or at least sited in positions where they would be most effective in reducing casualties. Until this happens, whether I agree with them or not, I am prepared to live with them, because there's not a lot I personally can do about them.

[streaky]

sqwib said:

streaky said: Anything that is not illegal and at least buys some time to slow down would be of interest to many PHers (if I read their posts correctly ) Fair point, but I don't think number plates are as important as you say. Lasers will reflect from any surface. Bikes don't have front plates but can still be 'lasered'. ...

But, if my schoolboy physics has not deserted me (and assuming Scotty's assertions still how water aboyt the laws of physics ) the reflection will be at an angle determined by the plane of the surface to the beam. The greater the scatter, the less the received signal, and the less accuracy. I recall a case from many years ago where a Lotus Elan (I think) driver successfully demonstrated that the *radar* pluse had reflected off one of the spokes of his k/o hubs ... which was travelling at a higher rate than the car. Just musing - Streaky

[Mr2Mike]

The flaw in the plan is that the reflective material used in number plates actually contains thousands of tiny corner cube reflectors. A corner cube reflects light directly back to the source, making it ideal for number plates etc. However this means a laser hitting the number plate at an angle will still have a significant return signal.

What you could do (quite legaly I believe) is to make a "passive" laser jammer by having a reflective surface that moves in the opposite direction to the car. In practive this would have to be something like a paddle wheel with reflective paddles, half sticking out of the bonnet etc. Not overly practical...

[kevinday]

IIRC a number plate must be mounted in the vertical plane or within a few degrees, therefore not legal. Also you would need to consider increasing the height of the number plate so that it was still legible (using tall letters).

[deltaf]

My front number plate is a modified one.
The outer plastic perspex front is cut down to the absolute bare minimum for regulation size/shape etc.
The letters are also normal size/space, so no legal issues there.
The letters are stuck on in the normal fashion by the signwriter from behind.
The white background is actually sprayed on. Its just a sprayable tippex, and looks in the daylight just like a normal plate.
Only at night is the difference noticable, but even then, it just looks like a dirty plate.
The front side of the plate is buffed back using scotchbrite pads to remove the shine of the plastic, and it looks very slightly frosted, although not enough to draw attention.
I suggested this idea to steve on the uk speedtraps site for testing. It works quite well by all accounts, decreasing the distance by which they can get a fix with laser in the region of around 200 feet.
So thats 200 feet less distance they have to play with, and 200 feet more for you to see them in.
Even if it only worked by 50 feet, thatd be a result.
Every little bit helps.

[marvelharvey]

deltaf said:

My front number plate is a modified one. The outer plastic perspex front is cut down to the absolute bare minimum for regulation size/shape etc. The letters are also normal size/space, so no legal issues there. The letters are stuck on in the normal fashion by the signwriter from behind. The white background is actually sprayed on. Its just a sprayable tippex, and looks in the daylight just like a normal plate. Only at night is the difference noticable, but even then, it just looks like a dirty plate. The front side of the plate is buffed back using scotchbrite pads to remove the shine of the plastic, and it looks very slightly frosted, although not enough to draw attention. I suggested this idea to steve on the uk speedtraps site for testing. It works quite well by all accounts, decreasing the distance by which they can get a fix with laser in the region of around 200 feet. So thats 200 feet less distance they have to play with, and 200 feet more for you to see them in. Even if it only worked by 50 feet, thatd be a result. Every little bit helps.

Now there's an idea! Good work deltaf!

[trefor]

deltaf said:

My front number plate is a modified one. The outer plastic perspex front is cut down to the absolute bare minimum for regulation size/shape etc. The letters are also normal size/space, so no legal issues there. The letters are stuck on in the normal fashion by the signwriter from behind. The white background is actually sprayed on. Its just a sprayable tippex, and looks in the daylight just like a normal plate. Only at night is the difference noticable, but even then, it just looks like a dirty plate. The front side of the plate is buffed back using scotchbrite pads to remove the shine of the plastic, and it looks very slightly frosted, although not enough to draw attention. I suggested this idea to steve on the uk speedtraps site for testing. It works quite well by all accounts, decreasing the distance by which they can get a fix with laser in the region of around 200 feet. So thats 200 feet less distance they have to play with, and 200 feet more for you to see them in. Even if it only worked by 50 feet, thatd be a result. Every little bit helps.

Now there's someone dedicated to the cause!

[cptsideways]

I thought I was the only one doing this!,

Grey primer is even less reflective than white paint, & those black numbers dont have to be solid black they can be opaque too. see what happens if you put reflective backing behind parts of them.....

Still looks like a dirty plate.