Safe Speed Forums

Thanks to the tripod the unit sits on, the setup is more akin to a well-balanced rifle than a hand-held pistol.
Also, the bullet/emission ‘spray’ is much wider, about 80cm compared to 1cm, so there’s no need for sniper-type accuracy anyway.
I think it reasonable that someone could hit a 4.5cm diameter target, with a mounted rifle, from 15m.

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Views expressed are personal opinions and are not necessarily shared by the Safe Speed campaign

The comparison between a laser spedmeter and a gun/rifle is not really valid.

The instrument is shoting light and you would need to compare it with a torch rather than a gun; could you hit a motorcycle with a torch beam and do it reliably? The answer for all but the more physically challenged is yes in my opinion.

The docking system looks STRAIGHT down the AXIS of the two vehicles, and gives a read out of the distance between them, and in particular measures their speed of closure. It is the accuracy of the distance, and the speed of the readings which are critical to the operation, but looking down the axis - i.e. being directly ahead of the vehicle being measured - is rare in measurements of road vehicles, otherwise the operator would be in danger of being run down!
Quoting their use in space by NASA is a red herring - it is like comparing the use of a ruler to measure a flat peace of paper with a similar piece of paper wrapped around a cylinder! You can do it - but a lot more care is required!

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Time to take responsibility for our actions.. and don't be afraid of speaking out!

Are torches that illuminate a 4.5cm spot 15m away commonplace? How many of this style do you have?

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Views expressed are personal opinions and are not necessarily shared by the Safe Speed campaign

Maybe a shotgun would make a better analogy! The road sign near Blackwell in Bowness showed a beam spread of about 9 inches - from not too far away at a guess!

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Time to take responsibility for our actions.. and don't be afraid of speaking out!

The distance of the biker from the leading vehicle at the moment when the speed reading was displayed.

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Views expressed are personal opinions and are not necessarily shared by the Safe Speed campaign

That's quite funny if you've seen any of the other equipment they have to work with in space.
I do believe I have seen a video of space shuttle docking where one of the astronaut guys way pointing a LIDAR device out the window at the ISS to get speed/distance readings. It could have been the same type of device, but being used for a very different reason, and I'm pretty sure NASA have more than one way to measure the distance for when their LIDAR device fails. If they miss the ISS they hit space, not the ground or another vehicle, and they take more than one reading.
Presumably this is as accurate as the retraction mechanism for the solar arrays it took them about a week to retract, with a lot of poking around involved? Is it as accurate as the circuit breakers powering the altitude control computers which turned off soon after attaching a new solar array which they had to "bridge" to get power again?
What's the maximum speed this LIDAR device is allowed/checked/calibrated to measure?

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Andrew.

this particular model is only allowed inth uk to 999.9 metres, simply due to the 5 digit back panel, it works far beyond that

max speed cannot remember either 250 or 299 mph

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now retired

I've registered on a new website/forum dedicated to calling for these devices to be openly scrutinised.

governmenttransparency.net

I've given a technical explanation of how the LTI can resolve distances with precisions beyond what the 'clock speeds' will allow.
I've also started to give a list of possible sources of errors of the LTI; the list can be added to and discussed, so feel free if you can think of any (this forum seems to be over-run with engineering types, so some here should be interested ).

Both are on this page.

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Views expressed are personal opinions and are not necessarily shared by the Safe Speed campaign

I believe the charge against the 150mph biker is for dangerous driving, not speeding. Let me recap some thoughts on the "dangerous driving" part of the case.

I believe I can prove there is no evidence to show the driving/riding was dangerous.

Logically, if the biker looks slow for 150mph, then the distances involved are inherently also greater than it looks. We know the camera has one heck of a telephoto setup (400mm sitting on a 6x crop factor imager – all this detail is in the current manuals). That setup has about 50x skew of perspective compared to what the human eye sees.

This little sign doesn’t look like it is 945m away from the gun in the video, but it really is.


I have shown the distance from the biker to the leading traffic to be ~200m in this post:
viewtopic.php?p=222188#p222188
The same process that shows the speed to be 150mph will inherently show the distance to the leading vehicle to be 200m (at the time of the end of speed reading [will be greater if distance is at the midpoint of the speed reading]).

The large gaps, coupled with know deceleration rates of these bikes at high speed, supported by the fact the biker hardly had to apply the brakes (the brakes were applied for only ~1.1 seconds of the 5 seconds from the ping to the end of the video clip), shows the biker had the situation well under control.

I have shown how the riding in this case wasn’t dangerous, within a Pistonheads thread:


Some relevant snippets from that thread are summarised below:

>>>>>>>>>>>>

At the time of the end of the speed reading, the van in L3 is 22 lane markers ahead of the biker, which is 198m.
Assuming the van is at a legitimate speed (70mph), the biker would have to scrub off the 150 – 70 = 80mph DIFFERENTIAL within that 198m gap between them.

Assuming a linear rate of deceleration, the biker would have to slow at an average rate of:
a=VV/2d = ( 80/(3600/1609.3))^2 / (2 * 198) * (3600/1609.3) = 7.2mph per second.

This translates to 11 seconds of braking at 7.2mph per second before catching (and not colliding with) the leading vehicle. This is a gentle rate of deceleration.

>>>>>>>>>>>>>

The aerodynamic drag (drag to inertia ratio) yields a significant amount of deceleration at 150mph type speeds, approaching 85kw of ‘slowing power’ acting on 300KG (wet weight and rider).
Including transmission losses, but not engine losses, that equates to:
85kW / (70.6m/s * 300KG) = 4.0m/s @ 158mph, translating to about:
(150/158)^2 * 4.0 * (3600/1609.3) = 8mph/sec at 150mph.
This drag means the biker can slow down at a much greater rate than the standard low-speed stopping distance guides state, because that drag force presents no load on the tyres or the brakes; the deceleration from those factors are additional.

Thus at the higher speeds (up to the 150mph), the biker will already slow at the rate needed to avoid collision, even without consideration of engine losses, or application of the brakes.
When considering engine losses and the fact the biker also braked, the resultant deceleration will far exceed that needed to avoid a collision with the leading vehicle.

>>>>>>>>>>>>

Considering the worst-case scenario of the van braking hard from 70mph (reasonable considering it was passing traffic shown to be doing 55mph) with the biker doing 150mph 200m behind, the total stopping distance available to the biker would have been:
200 + [(31.3)^2 / (2*9.80665*0.67)] + [0 (thinking time doesn’t apply)] = 200 +75 + 0 = 275m.

Assuming standard forces for an old car with drum brakes as per Highway Code (2/3 G, 2/3 sec; I don’t know the typical braking performance figures for these sports bikes):
[(67.05)^2 / (2*9.80665*0.67)] + [67.05 * 0.67] = 342 + 45 = 387m

However, we know the drag effect at those high speeds will add 8mph per second to the deceleration (for free as drag doesn’t present additional load on the tyres or brakes), which equates to an additional 0.36G (at 150mph).
Also, a biker doesn’t have to move a foot from one pedal to another to brake (and will likely be very ready to react in that situation)
Assuming 1G, 0.5 secs and 150mph = 262m. This is within the distance needed to avoid the van even if the van driver braked hard.

>>>>>>>>>>

The gap to the leading van was about 200m. However, the van itself was moving and the biker could see there was nothing in front of it (the lane the van changed into was clear of other traffic), so the biker can reason that it won’t suddenly turn into a static brick wall. Hence by the time the biker had reached that 200m point some 3.52 seconds later, if the van doing 70 it would have been a further 110m down the road, so reasonably extending the safe stopping distance.



The bike covering 200m in those 3.52 seconds means it was doing an average speed of about 126mph over those three seconds. At the start of those 3 seconds, if the biker was doing the 150mph, at the end of that duration the biker would very likely have been doing 2 x 126 – 150 = 102mph (assuming a linear rate of deceleration, which is quite possible if the biker was gearing down when appropriate such that the engine braking would be greater, thus offsetting the reduction of the drag effect).

This rate of change of speed (48mph in 3.52 seconds = 13.6mph per second = 0.62G) is in keeping with the expected deceleration (drag, brief braking and engine losses).

The biker need scrub off a differential of 102 - 70 = 32mph in that 110m gap (assuming the van was doing 70).

Assuming a linear rate of deceleration: to prevent a collision, the biker would have to slow at an average rate of:
a=VV/2d = (32/(3600/1609.3))^2 / (2 * 110) * (3600/1609.3) = 2.1mph per second. This is trivial and easily within the bounds of aerodynamic drag and engine losses.

Again considering the worst-case scenario of the van braking hard from 70mph with the biker doing 102mph 110m behind, the total stopping distance available to the biker would have been:
110 + [(31.3)^2 / (2*9.80665*0.67)] + [0 (thinking time doesn’t apply)] = 110 +75 + 0 = 185m.

Assuming standard forces for an old car with drum brakes as per Highway Code, but with the faster reaction time (as before):
[(45.6)^2 / (2*9.80665*0.67)] + [45.6 * 0.50] = 181m.
Again, this is within the distance needed to avoid the van even if the van driver braked hard.



Additionally:
- the van driver is unlikely to have pulled out into lane 1 if there was traffic close behind.
- the biker would not have sat up (14:30:00NR32) if he was going faster than he thought safe to do so.

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Views expressed are personal opinions and are not necessarily shared by the Safe Speed campaign

Sorry Steve. Nice try but every fule noes "Speed Kills". Which is why the motorcyclist is in a coffin. (n.b. that is irony)

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When I see an adult on a bicycle, I do not despair for the future of the human race. H.G. Wells
When I see a youth in a motor car I do d.c.brown

Thanks Dave.
If it transpires that such speeds are automatically classed as dangerous driving, and if the defence doesn't try to test that guideline, then IMO it is extremely likely that biker will automatically be convicted.

I've gone through the clip in great detail (you must know me by now) and I cannot find any valid means to achieve a speed error, of 150mph, from the gun. I could explain why, but it has recently become apparent to me that RSS (they are watching) aren't as smart as they like to believe/portray, and I have no intention of helping them (they are/were part of the SCP misinformation machine).

Did anyone actually check my workings?

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Views expressed are personal opinions and are not necessarily shared by the Safe Speed campaign

Pleaded guilty under overwhelming prosecution evidence to dangerous driving at 150mph, driving without insurance and driving other than in accordance with a driving licence.

23 weeks imprisonment suspended for 2 years. 2 years disqual, extended retest and 200 hundred hours unpaid community work.

10% discount for guilty plea only because a whole trial was wasted with a not guilty plea.

I appreciate the prompt update. Thank you.

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Views expressed are personal opinions and are not necessarily shared by the Safe Speed campaign

BBC News Here

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Safe Speed for Intelligent Road Safety through proper research, experience & guidance.

Maybe he was trying to have his cake and eat it.

He won’t be puddin’ on a smile now.

I read his bike’s scone.

He must be on the breadline after all that expense.

I think he’s rouened his career.




(Come on Graball, I know you can’t resist mate ).

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The views expressed in this post are personal opinions and do not necessarily represent the views of Safe Speed.
You will be branded a threat to society by going over a speed limit where it is safe to do so, and suffer the consequences of your actions in a way criminals do not, more so than someone who is a real threat to our society.

Dunno now.

If that news report is accurate; that he was almost completely inexperienced, riding without insurance and wrote his bike off soon afterwards, then I have somewhat less sympathy for him.
However, would an experienced rider with insurance have been treated any differently?

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Only when ideology, prejudice and dogma are set aside does the truth emerge - Kepler

What's that mean? He wasn't licenced for this bike?

He was licensed for a bike up to 25KW. The 633cc is well beyond that!

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Views expressed are personal opinions and are not necessarily shared by the Safe Speed campaign

In that case, it's even worse - unlicenced as well

But, would an experienced, insured, properly-licenced rider have been treated any differently?

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Only when ideology, prejudice and dogma are set aside does the truth emerge - Kepler