John,

The dashed lines used to designate the lanes are about a 15 feet long, with
an equal space between, thus you can use the lines as a gauge of distance.
I was taught this in Driver's ed about 35 years ago.

Jack

-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
John Bange
Sent: Saturday, June 21, 2008 3:21 PM
To: vanagon@GERRY.VANAGON.COM
Subject: Re: Drafting for better MPG

> I believe he was saying a length for every 10 mph of speed which, I
believe,
> is legal, in optimum conditions.

I have never heard this method of calculation used by any official
entity--- mostly just people repeated "what they've heard". It just
seems like a vague and ill-defined rule. What, exactly, is a "car
length"? Well, we know a Vanagon is 14-15 feet, but who can really
calculate, by eye, on the fly, from the driver's seat,  6.5 Vanagon
lengths at 65mph? And is that really enough? The "rule" I've seen from
 most government safety busybody agencies is "2 seconds in good
weather". Two seconds following distance is 190 feet at 65mph... which
is a dozen "Vanagon lengths".

--
John Bange
'90 Vanagon - "Lastwagen"
'90 Vanagon GL - "Wiesel"