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/
>
>
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