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From: /a3/c5215a/weheh/user@mhuxa.UUCP
Newsgroups: net.physics,net.auto
Subject: Re: physical laws of freeway traffic?
Message-ID: <15@mhuxa.UUCP>
Date: Tue, 14-Jun-83 09:00:02 EDT
Article-I.D.: mhuxa.15
Posted: Tue Jun 14 09:00:02 1983
Date-Received: Wed, 15-Jun-83 23:29:49 EDT
Lines: 20

A physical phenomenon that I have witnessed commuting to and from
work is what I call the "Venturi effect" (after the physical phenomenon
of fluids coursing through a pipe): if a car is stalled on a two lane
highway, the fastest lane will usually be the one blocked by the
stalled car.

The answer to why this happens is that as cars from the blocked lane
merge into the unblocked lane, the remaining cars in the blocked lane
speed up to fill the vacuum.  Unless the drivers in the unblocked lane
are especially aggressive and unsympathetic, the cars in the blocked
lane will be allowed to merge into the unblocked lane and drive
around the stalled car.

If a car gets stuck in the Holland tunnel, transit police will allow
cars in the blocked lane to pass the stalled car until the tow truck
arrives at the scene.  After the tow truck has moved into place
however, the unblocked lane will be given preference.

                                      R. Gordon
                                      mhuxa!weheh