From: seidl@midway.dcrt.nih.gov (Edward Seidl)
Subject: Re: Speeding & Radar Locking ...
Organization: National Institutes of Health, Bethesda, MD
Distribution: dc
Date: Fri, 24 Jul 1992 12:10:56 GMT

In article <1992Jul22.125320.7298@srg.srg.af.mil> dpipes@spica.srg (Dave Pipes x4552) writes:
>In article <1992Jul21.024212.9973@jhunix.hcf.jhu.edu> fieldson@jhunix.hcf.jhu.edu (Gregory T Fieldson) writes:
>>Subject: Re: Speeding & radar gun locking & on & on
>>Newsgroups: dc.general
>>In-Reply-To: <1992Jul20.231524.1576@srg.srg.af.mil>
>>References: <1992Jul15.195450.14966@monster.saic.com> <1992Jul16.173708.14300@srg.srg.af.mil> <NIGEL.92Jul17204210@rs733.GSFC.NASA.Gov>
>>Organization: HAC - Johns Hopkins University, Baltimore
>>Cc: 
>>Bcc: 
>>
>>I'll try to get my syntax and stuff right
>>>> stuff ommitted
>>something like...
>>> The autobahns were built in the 30s, and I bet they weren't made for 
>>> speeds much higher than 65
>>
>>Not so.
>>The autobahns I have been on were built so that they could be used as
>>runways for NATO jets if necessary.  Flat, wide and driving at 110 mph 
>
>That is the straight sections.  Same with the highways here, which are
>also part of the national defense system (but that may have changed a 
>year or so ago).  Any straight section of highway could have a very high
>speed limit.  It is the turns I was referring to, since the roads were
>laid out starting in the 30's.  Unless they were widened and made less
>curvy, the turn speeds should de a limit on road speed, and 65-70 mph
>would have been fast back then.
>>
>>greg fieldson
>>a tired grad student
>>fieldson@jhunix.hcf.jhu.edu
>>
>
>	David Pipes
>robear@digex.com

You might want to read an article which appeared in "American Heritage"
some time in the last year (sorry, I don't have the exact issue handy).
Anyway, it described the construction of the first modern "super highway"
in the US...the PA Turnpike.  This was in the late 30's, around the same
time as the original Autobahns, and it WAS designed with a 65 mph speed
limit in mind.

And for those who are claiming better gas mileage when traveling 65-70, here's
some counter anecdotal evidence...I used to think the same way, until on
one trip from Ga to Philadelphia, for reasons I don't remember my average speed
was limitted to just over 55, rather than my customary 65. Lo and behold,
my mileage went from ~50mpg to nearly 60 mpg (I have a CRX HF, so yes, I do
get that kind of mileage).  I think the reason people claim better gas mileage
at higher speeds is that they are travelling at one speed for a long time;
no starting and stopping.  I'm no auto engineer, but common sense would seem
to dictate that if at 65 mph my engine is doing 2000 rpm, and at 55 my engine
is doing 1500 rpm (which are very nearly the values for my car), I'm going to
burn less fuel at the lower speed.  My trusty hp 15c tells me that a 300 mile
trip at 55 will take 5.45 hours, or 490,500 revolutions 
(5.45 h=327 min x 1500rpm = 490,500 r).  The same trip at 65 will take 4.62 
hours, or 554,000 revolutions.  Even though the trip is much shorter time wise,
I've probably burned more fuel.  Granted, I'm not sure what the fuel/air mix
is at the two different speeds, but in general I think this simple logic
will hold, especially for older cars which don't have all the fancy electronic
carburation, etc.

Then again, I'd rather spend the extra fifty cents and get there sooner :-)

Just my .000138 yen.

Ed Seidl
--
Edward Seidl                                      DCRT/CSL Bldg 12A, Rm 2033
seidl@alw.nih.gov                                 NIH, Bethesda, MD 20892  

I'm not paid enough to have an opinion, much less express one for my employer.
Newsgroups: dc.general