Laser speed detection questions

[tinkerbell]

Also if you are so worried about the massive increase in the risk of injury/death in going from 100 to 140 then I suggest you don't travel along any sections of the Pacific Highway (or other roads) where it is signposted at 100km/h but it is single lane with no barrier between the two opposing directions.

who said i am worried?

as i said in post #26, the person who hit the double ton on the F3 at 1am proves that our roads/cars are capable of much higher speeds than they are sign posted for...

[a777]

um, well, it states (in the next line after the 21% figure):

Quote:
As speeds increase, serious injuries are usually found to increase at a faster rate than less serious injuries.

how is that not talking about "the chance of injury/death"

It might be talking about it, but not in any quantifiable manner, certainly nothing to do with 21% or "HEAPS" like you stated. :w:

Again,

"chance of injury/death in accident increased by 50*%
*it is actually much higher, but dont know exactly. but 100-140 must be HEAPS, if 100-110 is 21% increase**

ie you are trying to state that the chance of injury/death in accident increases by more than 50% which is just not backed up by your link.

[tinkerbell]

yes, you are right.

sorry.

[a777]

yes, you are right.

sorry.

No worries

[Shifty]

Touch wood, I am pretty good with (a) not speeding and (b) spotting radars... and I've been booked once in excess of 300m (handheld radar) and once in excess of 400m (camera). That means the reading would have started at something like 500m initially.

On both occasions there was no danger and in fact on the second offence, from 326m or something similar, the officer even agreed with me that I stopped very safely and in a controlled manner and that I could have stopped very easily from a much higher speed.

Goes to show there's not much discretion involved, all about the numbers. You cross the limit you're fodder... no matter how much you disagree with what's safe and what's not, you're gonna get fucked so just speed as little as possible without putting yourself in danger and stop complaining about fines because we can't and won't stop the government.

[Lobster]

I've often thought that a bank of pulse modulated IR LEDs (all running at a different pulse and duty cycle rates) mounted at the front of a car would do a great job at confusing the input stage of LIDAR units.

They did that on myth busters.... Didn't make a difference...

[Herve Villecha]

But is it a 100% accurate reading?

I believe they're supposed to be calibrated before use, but how often that actually happens, I couldn't tell you. The red dot follows the car once it's been locked on so that part is definitely accurate. The actual speed measurement depends on the calibration.

so

how do they "get the target in the middle" when its on the side of the car? do they swirve?

I know a time I got booked it was impossible for him to ping me for more than half a second. (it was round a bend, he was coming the other way)

Read the original post again. Take note of the term "hand-held".

[BigMuz]

What's the difference- just face facts that on normal roads now you CAN'T speed.

If you want to go for a blast head out bush or go to a circuit.

[Bozz]

muz, my original question is a technical question, not a sook. I still dont know how anyone but the best can accurately hold something much shorter than a rifle, without a shoulder support and accurately pinpoint a car for over a split second, over 100m away.

[BigMuz]

Did you consider that perhaps the electronics in the gun assist the cop in aiming and measuring your speed? I wasn't busting your chops mate, I just think that most of the time when you get done you deserve it.

Last time I got booked was coming back from QLD maybe 4 years ago, and I was over it and I hustled past a truck not far from home at 140 plus. Then I pulled back in and kept it rolling along without slowing too much to put some distance between me and the truck.

He got me by laser from about 300 metres away. He asked "why were you speeding?"
I said that I overtook the truck and pulled back in and I guess I didn't button off wuickly enough. He said "yeah, I watched you do 148 past the truck then you pulled back in and slowed to 130, so I'll book you for that. I understand that you need to get a bit of a run up to get past a B double but you should have slowed back down and then we wouldn't be having this chat."

Seemed fair to me, and also he had measured my speeed while I was a LONG way away and next to a B Double and his reeading matched my speed exactly.

[tinkerbell]

muz, my original question is a technical question, not a sook. I still dont know how anyone but the best can accurately hold something much shorter than a rifle, without a shoulder support and accurately pinpoint a car for over a split second, over 100m away.

um, it is not a laser like the one you point at things in a lecture theatre, or on a assassins rifle scope like on TV...

it is an IR laser, see MS Paint above for clarification...

for interest:

The lidar does not measure speed - it measures time of flight of each reflected pulse of energy from the target and the known time between pulses, converting it into a speed measurement.

[tinkerbell]

shit loads of info here:

http://www.ukspeedtraps.co.uk/speed1.htm

such as this picture:



Example of the spread of the Laser Beam over distance. (RIEGL LR90)

[Motorsportlady]

I do agree that we should not speed, particularly in built up areas, but I consider that some of the national highways could be opened up in speed higher than the 110km/h maximum on selected roads.

I regularly do advanced driver training courses! they remind me where I am getting lazy i.e. not keeping my head up and looking far enough forward, to hand positions on the steering wheel to maximise control in an emergency.

I realise these skills to the average driver are foreign, as the car is simply a tool or appliance to these people. I'd heard third hand that a girl's mother had told her sister that "She should only get an automatic licence as she had much more important things to think about while driving other than driving!" I cringed when I heard that, but I don't think this is unusual given the attention paid by other people on the road to their driving!

I dug up some interesting statistics on road accidents! Given theat the Cars are far better and I don't believe the criteria to get a licence has improved enough!

[Quote ABS] Road fatalities and fatality rates - 1926 to 2005

Australian road fatalities for the period 1926 to 2005 are shown in graph 22.19. Road fatalities per 10,000 registered vehicles and 100,000 persons for the same period are shown in graph 22.20.
Until 1970, each year other than during the Depression and World War II had seen a steady growth in motor vehicle ownership and a corresponding increase in road deaths. By 1970 the number of vehicles had increased twelve-fold over the number in 1926 and the road toll had increased about four times to reach its highest mark of 3,798 deaths. The number of fatalities per 100,000 people also peaked in 1970 at 30.4. The road toll in 2005 of 1,636 was less than half the 1970 figure (although higher than the 1,583 deaths recorded for 2004), while the number of fatalities per 100,000 people (8.1) for 2005 was less than a third of that of 1970. Also, while there were 8.0 road fatalities per 10,000 registered vehicles in 1970, this rate has decreased to 1.2 in 2005.[end quote]


I was actually looking for statistics comparing deaths in residential and city areas versus rural country. Does anyone on here work in an area where they could find this out?

Here's the Aust Bureau or Statistics site:_

http://www.abs.gov.au/AUSSTATS/abs@....7?opendocument

[tinkerbell]

I was actually looking for statistics comparing deaths in residential and city areas versus rural country. Does anyone on here work in an area where they could find this out?

some stuff from SA:

http://www.transport.sa.gov.au/pdfs/...crash_2003.pdf

page 8...

[2JZR31]

http://blogs.drive.com.au/2006/11/no...peedy_day.html