Path: utzoo!mnetor!uunet!lll-winken!lll-tis!mordor!sri-spam!sri-unix!quintus!pds
From: pds@quintus.UUCP (Peter Schachte)
Newsgroups: comp.sys.amiga
Subject: Re: Amiga in the news
Message-ID: <728@sandino.quintus.UUCP>
Date: 3 Mar 88 21:37:55 GMT
References: <2089@polya.STANFORD.EDU> <379@coplex.UUCP>
Organization: Quintus Computer Systems, Mountain View, CA
Lines: 23
Keywords: Computer controlled braking.
Summary: No, reaction time is the main issue.

In article <379@coplex.UUCP>, jim@coplex.UUCP (Jim Sewell) writes:
> Wouldn't the problem still exist with driving too closely?  It would still take
> XX feet to stop a charging car traveling at YY mph.

No.  If you assume that both cars (the one in front in a panic stop and
the one in back trying not to plow into him) have equally good stopping
distances, then reaction time is the determining factor.  If you're one
foot behind another car that goes into a panic stop, and you brake just
as hard as he does, you wouldn't hit him.  (No, I wouldn't try it,
either, but it makes sense in theory).

It seems to me that what a program like this should consider in
determining whether or not to apply the brakes is not just distance
from another vehicle, but RELATIVE VELOCITY.  If another car is 100
yards away, but headed at you at 110 relative miles per hour (he's
in the wrong lane), you probably want to be warned sooner than if he 20
feet from you, but going at the same speed.  The program should
probably know it's reaction time, though, and your current speed, and
raise an alarm if another car gets so close it couldn't stop in time if
he brakes.
-- 
-Peter Schachte
pds@quintus.uucp
...!sun!quintus!pds