WHEEL SIZE, CALIBRATION, TYRE PRESSURE and VEHICLE SHAPES Feb 24, 2016 0:42:03 GMT
Post by Administrator on Feb 24, 2016 0:42:03 GMT
SPEED SURVEYS and calibration accuracy as well as shape.
how does tyre size effect fuel consumption?
This is a multi wheen vehicle! if it drives over a speed survey cable on the road... does the cable truly know it is one vehicle?
I question a speed survey guy contracted to the local council.This is Tamworth and just after I was going through the section where they have 20mph speed limits by speed cameras!? do they really set the cameras to 20mph outside the school?! there are quite a few other areas like this in Tamworth!
here again is the video i did ages ago of the POLICE out doing checks and surveys in Doncaster (not the council) but not out cleaning or checking road signs are correct and legal as well as their own non required additional signs that do not effect legislation prescription requirements of othewr signs and are only there for the polices "extra help" (but not at traffic light cameras)
Online speed calculator.. if it is accurate.. or you could let your tyres down and try GPS for 1/2 a mile off the public roads to experiment?
Sorry for the photos being upside down.
I noticed that the speedometer doesnt rest exactly in the centre of zero anymore... so could it have come out of exact calibration? because as well, i did a GPS skitracks reading the other day and it was 0.2mph different.Also there is a drag effect and uptake effect... where the speedometer will be offset when either braking, or holding back compared to the acceleration push against it... and that should be taken into account if you are braking and being speed measured by a devive at the same time.
Also is the speedometer calibration set by manual mechanical adjustment or by the engine management system? can it be hacked while driving? so to adjust vehicle speeds and be used to effect travel times, if say the government wanted to use secret means to arrange for vehicles to be in ecact places at exact times? and how about the fuel guage? i saw a guy today at Washington, on the A1 just ran out of petrol 100yards before the services! what are the chances of that!?
also i checked the road signage and there are wrong size repeaters for national speed limit after the Tyne bridge. and there was an accident on the A19 south... never see them ever on there.. and the Highways will be liable because the national speed limit signs are illegal! and there were two highways vans and a police car and another highways patrol van southbound again! and i stopped to ask questions and they agreed with me! i will post about it in the main hello & welcome thread..
anyway... i found this online calculator to give you an idea of how much a differance it makes to change the wheel size or tyre size or if say you lost air pressure in the tyres
i did examples of a compaarison between smallest and largest wheel sizes then vice versa...
and also a van with two slightly different wheel sizes.... and alsso a van and a car
so there is a HGV with mini wheels.... a mini with HGV wheels..
a car with van wheels, a van with car wheels and a van with different wheels that are from a similar model...
this gives you a general idea of how it can considerably effect the speed reading! also... a speed survey has no idea at all how long the vehicles are wheel to wheel, how many wheels they havee, or really what size tyre is riding over it! i question the technology in the devices for speed surveys and i got mystery chance to talk to a guy in Tamworth about it yesterday! anyway... sorry that these photos are all jumbled up... but i will let you work out which wheel size is which vehicle and compare! in fact.... the guy i question admits that the device could never be used to prosecute drivers...it is only really a very average speed survey and a traffic tally... so question is... why do the police use them as well? and why are the police not doing sign surveys as well?