Pyramid Comment

This journal takes an alternative view on current affairs and other subjects. The approach is likely to be contentious and is arguably speculative. The content of any article is also a reminder of the status of those affairs at that date. All comments have been disabled. Any and all unsolicited or unauthorised links are absolutely disavowed.

Sunday, October 02, 2011

Speed Limit Increase

Understanding Speed Limits
Know Your Speed Limits
UK Speed Limits
Speed Limits
80mph limit criticised
Oil Production Increase
Economical Driving - The Physics

A limit to the highest legal speed for a particular road is not necessarily a safe speed. It is the maximum  speed permissible. Philip Hammond (Transport Secretary) said the current limit (speed on roads - DA), introduced in 1965, was out of date due to "huge advances in safety and motoring technology". This is pandering to the car manufacturers and conveniently ignores protecting road users be they driver, passenger, pedal cyclist or pedestrian. Drivers 'controlling' cars capable of high speed include the inadequate driver who considers him/herself a Stig [ = Gits (?) backwards -  DA].

Talking up the improved safety in cars does not consider that reaction speed remains unchanged. The time available to react to a situation is reduced for a particular driver as the faster the car is travelling the further the vehicle will have moved before any avoiding reaction to the situation can be made. Reaction speed and time involves recognising a hazard and making a decision about the necessary action to be taken. If the wrong decision is made then it is unlikely that time will be available to correct the error. The higher the speed the less chance of corrective action. The inevitable is a negative outcome and possibly (probably - DA) a fatal one if travelling at 80mph or even ‘just’ 70mph. Seat belts aren’t particularly effective above 30mph or thereabouts.

A real advantage of a rear seat belt at survivable speed is restraining a human missile (child or adult) thrown forward in the event of rapid deceleration after collision impact.

  • Motor cyclists are excluded since they form a totally different argument. Of those who ride powerful motorcycles, many (probably the majority by far - DA) seem to imagine themselves exempted from laws that apply to everyone else. As an estimate of all RTA (road traffic accident), bikers amount to just 1% of road users, but account for 25% of those killed.
Statistics intended to describe the situation do not clarify reality. The apparent reduction in the number of fatalities (per billion vehicle miles) fails to consider that the number of road users over the same period increases. The logarithmic scale distorts the picture considerably. This is a similar distortion (though not erroneous) to the apparent violence of an earthquake. The Richter magnitude scale is logarithmic and an increase of a single unit is actually a x10 increase in the severity. A change or 5 -> 6 = x10 and 5 -> 7 = x100. Radiation exposure is also logarithmic (exponential). A danger with statistics for the unaware.
    70 miles in 1 hour against 80 miles in 1 hour is simply an increase of 10 miles distance in the same 60 minutes. At the same speeds, a distance of 7 miles would take 6 minutes (360 seconds = 70mph) and 8 miles also 6 minutes (80mph). Put another way, the same 7 miles at the higher speed would take just over 300 seconds = 5 minutes. The journey would be shortened by 1 entire minute.
      • Hold ups (junctions, roundabouts, traffic lights) and other speed-affecting problems would easily neutralise this 1 minute
      Advances in technology are claimed to have made cars much safer, contributing to a drop of more than 75% in the number of people killed on British roads since the 70mph limit was introduced. A drop of 75% may describe a 'reduction' in total numbers, but does not indicate the number of fatalities on British roads. As the number of 'users' increases, the 75% decrease is of an increasing quantity.

      Green Party spokesperson Jenny Jones: "This is a mad idea just at the time we should be worrying about fuel economy and emissions. Putting the speed limit up will be worse for both. So much for the 'greenest government ever'." (Most backward and growth driven - DA)

      Economical Driving

      Hammond is the government champion of increased speed. Getting from A to B just a bit quicker. If this 'bit' is hundreds of miles away then travelling by plane can have true meaning (ignoring the pollution issue, the vast quantity of fuel used, travelling to an airport...  - DA). If just a few miles away, then increased speed of travel does not 'quicken' the total journey by much.

      Many complain about the rising cost of fuel. Many do not and make considered moves to reduce their costs   The fall in petrol sales 'cost' the Treasury nearly £1bn over the six months to June. (It doesn't cost the Treasury anything as it's just revenue that never materialises - DA). Some of those who do complain are deluded and is evidenced by the uneconomical driving techniques. Racing around with hard acceleration of large-engined vehicles. The increased fuel consumption is enormous and the time savings negligible on short town journeys. Government loses out on tax revenue with the rise in numbers of careful drivers. This explains the requirement to 'sell' more petrol. It’s a vicious circle: the cost of fuel escalates so the number of economical drivers increases and tax revenue decreases as consumers are getting smart. But not smart enough. Government ensures fuel prices rise to compensate (they really do ‘influence‘ DA).

      The environment and conservation of global oil 'reserves' do not matter and is suggestive evidence that there is no actual long-term shortage. The growing air travel business also conflicts with both of these arguments. Just the continuing and self re-enforcing message that there is a shortage to justify rising costs for all.

      There are some fascinating statistics put out by Jaguar for their XF saloons. All mixed up between the two extremes of models, from the cheapest diesel powered XF Saloon 2.2D SE (£30,950) to the most expensive XF Saloon 5.0 V8 SC XFR petrol engine model (£65,350). It's really about comparing what you get (or expect to get) for your money. Consider: 0 -> 60 mph in 8 seconds or 4.7 seconds. Although it appears to be roughly twice as fast to accelerate, actually the slower one takes just an additional 3.3 seconds. But it's £34,400 cheaper. Not really much of a speed advantage for such a huge cost overhead. But then the extra £34,400 enables a top speed of an additional 15mph (140mph -> 155mph). This works out at about a 10% maximum speed increase for the additional 110% purchase price for the performance advantages of almost double the standard acceleration 4.7s v 8.0s (0 -> 60mph). Moreover, town driving returns 15.1mpg (V8) against 42.8mpg for the 2.2D. Comparative out-of-town driving yields 32.4mpg and 58.9mpg, respectively. These are the official Jaguar figures even though they are extraordinary.

      Rolls-Royce unveiled the £305,000 gas-guzzling British-built Phantom Drophead Coupe. Arguably the safest convertible in the world. With a kerb-weight of three tons, the massive 6.75 litre V12 engine will propel it from rest to 62mph in just 5.9 seconds. There is a claim that 17 miles to the gallon is achievable from this two-door four-seat convertible 'fast tank': 3 tons taken from 0 -> 62 in 5.9 seconds? More like 2-3mpg? Someone who can afford the RR in the first place is unlikely to be bothered by consumption figures. Exhaust emission would be vast. The six speed car develops 453 brake horse-power - about the same as five Ford Fiestas - though the top speed is being electronically limited to 149mph (why bother? - DA). Road wheels are claimed to run for 100 miles at 50mph when punctured - eliminating the need for a spare. A psychological trick: RR vehicles don't get punctures and don't need spares (you can imagine the salesman telling that one - DA!!). The problem is, of course, that the slow puncture carrying three tons won't be noticed until the tyre is dangerously flat.

      This is not Conspiracy Theory, but simply
      an education in government economics

      70mph -> 80mph = 14.28% increase in speed and the kinetic energy (caused by motion) is given by ½mv². The energy is related to the square of the speed and ½m(70 x 70) = 2450 and ½m(80 x 80) = 3200. The dimensions for mass and velocity cancel out leaving the comparison simply between 2450 and 3200 that represents a 30.6% increase. The increase in speed has more than a doubling of the corresponding collision energy. The impact on crash is much greater and consequently the survivability of the higher speed crash is much less.