[From Fred Nickols (2010.06.13.1647 CDT)]
My wife and I have spent the past several days driving
cross-country in our motor home, returning to Ohio from several months spent
out west. (We’re in Springfield, MO right now.) I do most of
the driving and I have had ample time to observe and reflect on my driving
behavior. For now, I’ll focus on the basic issue of staying
in my lane.
Language is important here. If you were to ask me
“What are you controlling for?” I would probably answer something
like “Staying in my lane.” Or, more specifically, “staying
in the center of my lane.” But if you were to ask me what I
am trying to control, I would probably respond with something like “The
position of the motor home with respect to the lane.” I think
there’s an important difference.
The notion of “staying in my lane” represents to
me an abstraction, some imagined state maintained over time. But if you
ask, “How do you know you’re in your lane or in the center of it?”
I am forced to refer to some perceptions, more specifically, some perceptions
that are a large part of what I see when looking out the windshield and,
occasionally, in my rear view mirror and the TV display over the dash (from the
TV camera mounted on the rear of the coach). As plainly as I can put it,
I am trying to achieve and maintain a certain view when looking out the
windshield from my driver’s seat. More about the specifics of that
view in a moment.
Driving a 40 foot motor home is like driving a billboard
down the highway; it is extremely susceptible to the effects of wind and the
drafts from passing semis. There are many and occasionally quite strong
disturbances to and significant perturbations in the position of the coach
(thanks again, Bill P for that very useful distinction). Some of the
things I observed follow, in no particular order.
What I want to see when looking out my windshield is a view
that matches what I know that view looks like when I am centered in my
lane. How do I know that view out my windshield is a match with the coach
being centered in the lane? Well, I can look in my rear view mirrors (the
panoramic sections of those mirrors) and I can see the bottom edges of the side
of the coach in relation to the left lane marker and the right lane
marker. The view I want when looking out the windshield coincides with a
view in my rear view mirrors of the sides of the coach being inside the left
and right lane markers by about the same amount (about a foot). (FWIW,
the standard lane width is 12 feet and my coach is 8 feet wide, so I should see
two feet on either side but it sure looks more like one foot than two. Oh
well, some measurement will clear that up.)
Now, as to that view I want when looking out the
windshield…
that intersects with the top of the dashboard on the left and the right.
One piece of the view I rely on and try to achieve and maintain when driving is
that the dashed center line (left lane marker) is just a wee bit to the left of
the left intersection of the curve of the top of my steering wheel and the
horizontal plane of the dashboard.
My windshield is divided into two big sections, separated by
a vertical bar. It intersects with the top of the windshield housing and
the bottom of the windshield housing. Another piece of the view I rely on
and try to achieve and maintain when driving is that the solid line (right lane
marker) is a wee bit to the left of the bottom intersection of the vertical bar
and the windshield housing. It also happens to be the case that, when I
am centered in the lane, the solid right lane marker bisects the arm of the
driver’s side windshield wiper.
I can focus on any of these three main components of my view
out the windshield and use any of the three independently to maintain lane
position. I know; I’ve tried it. However, doing so requires
me to essentially shift my view from what is generally out in front of me to
what is very close and up front. That is not conducive to safe
driving. Nevertheless, testing those components did validate their utility.
So what I want to see is this full-field view of what is out
in front of me and, at the same time, also be aware of the relationships
between the lane markers and the intersection points described earlier. I
can do that. I don’t have to stare intently at any of the three
components to “see” them and see them in relation to the lane
markers.
What I do when I’m driving is simple enough, I turn
the steering wheel right or left to maintain alignment between what I see and
what I want to see; I don’t think about it, I just do it.
If there is no wind and the road is essentially flat and
smooth, my turning of the wheel is slow, slight and infrequent.
If there is a strong cross wind from a passing truck, my
turning of the wheel is much more rapid, frequent and involves greater amounts
of turn.
I also noticed something else: My steering wheel has a
cross-bar across its diameter. The top of that cross-bar is horizontal on
a flat, no wind surface. At times, it has a very slight left tilt to
compensate for a slightly tilted roadway on which the coach tends to drift to the
right.
That top cross-bar stays slightly turned to the right when I
have a cross-wind from the right.
So much for observation and reflection. Now, back to
PCT.
It seems to me that my “reference signal” for
keeping the coach roughly centered in the lane is visual in nature; literally,
my recollection or recalled image of what I should see when looking out the
windshield. That image seems to me to be at the configuration
level. What I see, my perceptions, have a quite a bit more dynamics to them:
the coach is speeding down the highway and the lane markers are rapidly moving
toward and disappearing underneath the intersection points mentioned
earlier. At a higher level, my goal or intent or reference signal for
“staying in my lane” is much more abstract, perhaps at the
principle level. In any case, it seems to me that there are at least two
levels of a hierarchy at work.
Speaking for myself, I’m fascinated by what I’m
observing and learning. And so I’m posting these musings from my
motor coach.
Now I’ll ask y’all: Does any of this have
any interest or value? I ask this not because I’m looking for
confirmation or anything else for that matter; instead, it seems to me that we
have lots of drivers, driver training courses, and even driving
simulators. Might there not be some fertile ground there for some PCT
research that everyone who drives could relate to?
We’re scheduled to be back home in Ohio on Tuesday
afternoon so I’ve still got some limited time for experiments. J
Regards,
Fred Nickols
Managing
Partner
Distance Consulting LLC
1558 Coshocton
Ave - Suite 303
Mount Vernon,
OH 43050-5416
“Assistance at a
Distance”
···
From my seat, the top of the steering wheel forms an arc