I started all this!
I now have 42 emails on this subject - mostly from RTT and mostly
useful. I am now wading through various reports that I have gathered.
Thank you for your contributions.
Michael Paine
mailto:[log in to unmask]
John McK Lambert wrote:
>
> Hello to John and Bob and other parties.
>
> Details are:
>
> Two 55 watt headlights require 110 watts of electrical energy.
>
> Efficiency of electrical system is 70% or a little better, and engine is 25%
> or a little worse.
>
> Hence 110 /0.7/0.25 gives engine energy input requirement of 630 watts per
> second.
>
> I watt per second = 1 joule. hence over an hour 2.3 mega joules of energy
> are required.
>
> Energy content of liquid fuels are around 40 MJ per litre. Hence extra fuel
> consumption is about 0.06 litres per hour. Assuming an average speed with
> lights on of day 75 km/h and 150000 km per year for large interstate
> transport trucks, then 115 litres of additional fuel will be required which
> at 95 cents per litre equals around $110 per annum. Of course for cars doing
> about 18000 km per year and averaging say 45 km/h the cost will be more like
> $20 per annum
>
> In addition there are filament replacement costs et cetera
>
> regards
>
> John Lambert
> ----- Original Message -----
> From: "IS Edit" <[log in to unmask]>
> To: <[log in to unmask]>
> Sent: Wednesday, September 11, 2002 12:23 AM
> Subject: Re: **SPAM** Re: Daytime running lights
>
> > Hi, John.
> >
> > Haven't seen you since the Maroochydore Conference.
> >
> > I got those figures from an engineer with a large American engine
> > manufacturer as he was driving his car speaking on a mobile phone. A
> second
> > contact has not got back to me yet. Sorry if not accurate, I replied
> quickly
> > to keep that interesting conversation flowing. Thanks for the correction.
> >
> > LED technology could make some sense for DRL. The right LED at a
> reasonable
> > price could well change the equation.
> >
> > Cheers,
> >
> > Bob Murphy
> >
> > ----- Original Message -----
> > From: "John Woodrooffe" <[log in to unmask]>
> > To: <[log in to unmask]>
> > Sent: Tuesday, September 10, 2002 11:30 PM
> > Subject: Re: **SPAM** Re: Daytime running lights
> >
> >
> > > Bob
> > > This discussion topic has developed into a very interesting debate.
> > > Australia certainly is unique and has many good reasons to apply a
> > > different approach to problems. However it is my understanding that
> > > the Australian horse is roughly the same size as the Canadian and
> > > therefore I would expect the horsepower calculations to be similar.
> > > For the 14 volt and 8 amp current figures you have selected, the HP
> > > estimate of 1/2 is too high by a factor of about 3. HP= (volt x amp x
> > > eff)/748
> > >
> > > As you say it is important to separate the safety benefit attributed
> > > to a certain action from the costs. However it is equally important
> > > to examine ways of reducing the costs to make the safety initiative
> > > viable. For example, taking you point about power consumption as
> > > stated, there may be a case for the development of low power diode
> > > lights for use in DRL applications. They have been used by the
> > > bicycle industry for years now with good success. Could this be a
> > > practical technology for DRL needs?
> > >
> > > John Woodrooffe
> > >
> > >
> > >
> > >
> > >
> > >
> > > -----Original Message-----
> > > From: The list is for the use of academics and others interested in
> > > technical, op [mailto:[log in to unmask]]On
> > > Behalf
> > > Of IS Edit
> > > Sent: Tuesday, September 10, 2002 3:38 AM
> > > To: [log in to unmask]
> > > Subject: **SPAM** Re: Daytime running lights
> > >
> > >
> > > Hi Robert and Phillip.
> > >
> > > The case has not been clearly made for daytime running lights in
> > > Australia.
> > >
> > > And regulation is not always the answer.
> > >
> > > There is the problem that DRLs suitable for use in dull climates
> > > (which
> > > often have darker vegetation than most of Australia) might not be
> > > effective
> > > under Australian (for instance) conditions.
> > >
> > > There is the issue that hot filaments are less durable than cold
> > > filaments
> > > and anyone that thinks that is not worthy of consideration has not
> > > spent
> > > much time on Australian roads (rough).
> > >
> > > On a 14 volt system it takes about 8 amps just to run headlights (if
> > > they
> > > were to be the ones to use in a bright, light coloured landscape).
> > > That uses
> > > up about 1/2 horsepower.
> > >
> > > Figuring about 125,000 litres per year fuel consumption for a
> > > reasonable
> > > longhaul truck in Australia, daytime running lights (assuming the
> > > truck is
> > > running during the day) would cost somewhere around $250 per year in
> > > fuel.
> > >
> > > That's about 1/4 of one percent of fuel at 100kmh which is where
> > > trucks
> > > cruise in most of Australia. Heavy vehicles are a small percentage of
> > > the
> > > total number of vehicles on the road but they have high exposure and
> > > use a
> > > lot of fuel.
> > >
> > > And by nature they are conspicuous in the first place.
> > >
> > > We don't need to argue that a car is more easily seen with lights on,
> > > but we
> > > need to quantify cost and benefit to see if it is worth imposing yet
> > > another
> > > regulation and another requirement on motorists and commercial vehicle
> > > operators. If such a move requires a Regulatory Impact Statement,
> > > you'll
> > > have to prove it is cost effective, anyway.
> > >
> > > Your sarcasm about putting yet another shilling in the electric meter
> > > cracks
> > > me up (did you used to live in Earl's Court, too?). I haven't seen too
> > > many
> > > academics or regulators yet (or anyone else either) with a good
> > > batting
> > > average for getting another shilling or two out of government
> > > treasuries for
> > > roads and infrastructure improvements in the interests of public
> > > safety.
> > >
> > > It seems some of them spend an inordinate amount of time imposing or
> > > trying
> > > to impose additional requirements on vehicle operators to achieve
> > > safety
> > > gains because it is too hard to get governments to return sufficient
> > > funding
> > > from road taxes of various sorts for maintenance and improvements.
> > >
> > > Regulation isn't the universal panacea, either. The US FMVSS121 and
> > > its
> > > premature imposition of anti-lock brakes comes to mind, as does the
> > > Australian regulation specifying a certain 7 pin trailer connector for
> > > heavy
> > > vehicles that was designed for car utility trailers and which had a
> > > rated
> > > capacity less than half of that required for many combination vehicles
> > > common on Australian roads. Seems Australian regulators when
> > > specifying the
> > > connector chose what the Europeans call a 12 volt plug (meaning a car
> > > plug
> > > because all their trucks are 24 volt) because most of our big trucks
> > > being
> > > US technology based have 12 volt systems. Uh huh.
> > >
> > > Where, pray tell is common sense really common, Phillip? I haven't
> > > found
> > > that place in 56 years.
> > >
> > > I spoke up because this old DRL issue has been around more times than
> > > a
> > > Melbourne tram and I still haven't seen any convincing argument in
> > > favour
> > > for Australia. Because I did so colourfully, it got a response, some
> > > of them
> > > very illuminating (pun intended).
> > >
> > > Much more and we would beat it to death.
> > >
> > > Cheers,
> > >
> > > Bob Murphy
> > >
> > >
> > >
> > > ----- Original Message -----
> > > From: "Robert A. Douglas" <[log in to unmask]>
> > > To: <[log in to unmask]>
> > > Sent: Tuesday, September 10, 2002 11:34 AM
> > > Subject: Re: Daytime running lights
> > >
> > >
> > > > I cannot believe the amount of email traffic this has generated.
> > > Why is
> > > so much being
> > > > made from this? Clearly, with lights on, a vehicle is more easily
> > > seen,
> > > even in daylight.
> > > > We need to argue this? And what is the problem with having them on,
> > > are
> > > people afraid
> > > > they'll have to put another shilling in the electric meter or
> > > something?
> > > >
> > > > The ONLY sensible complaint I've heard about cars running with
> > > headlights
> > > on during
> > > > the day is that it makes MOTORCYCLES (which typically run with
> > > lights on)
> > > somewhat
> > > > less visible themselves.
> > > >
> > > > R.A. Douglas
> > > >
> > > > Robert A. Douglas, BASc(CE), PhD, PEng
> > > > Senior Lecturer, Director of Studies (Forest Engineering)
> > > > geotranz - Natural Resources Geotechnique
> > > > and Transportation Engineering
> > > > New Zealand School of Forestry
> > > > University of Canterbury
> > > > Private Bag 4800
> > > > Christchurch, New Zealand
> > > > tel +64-3-364 2117
> > > > fax +64-3-364 2124
> > > > http://www.fore.canterbury.ac.nz/
> > >
> > >
> > > ---
> > > Outgoing mail is certified Virus Free.
> > > Checked by AVG anti-virus system (http://www.grisoft.com).
> > > Version: 6.0.385 / Virus Database: 217 - Release Date: 4/09/2002
> >
> >
> > ---
> > Outgoing mail is certified Virus Free.
> > Checked by AVG anti-virus system (http://www.grisoft.com).
> > Version: 6.0.385 / Virus Database: 217 - Release Date: 4/09/2002
> >
> >
--
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