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C00002 00002			COMPUTER CONTROLLED CARS
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		COMPUTER CONTROLLED CARS

		by John McCarthy, Stanford University

	There have been a number of proposals for  automatic  control
of  cars.     Mostly, they have involved simple servo-mechanisms that
sense a cable buried in the roadway  and  some  other  mechanism  for
sensing  the distance of the car ahead.  Such a scheme was studied at
RCA at the instigation of  Zworykin,  but  the  work  was  eventually
abandoned.

	In  science  fiction,  systems  in  which  a  single computer
controls all the cars in a wide area have been depicted  but  without
telling how the system would actually work.

	We  are  also proposing the computer control of cars.     Our
system requires a computer in the car equipped with television camera
input  that uses the same visual input available to the human driver.
Essentially, we are proposing an automatic chauffeur.  Our goal is  a
system with the following qualities:

	1.   The user enters the destination with a keyboard, and the
car drives him there.  Other commands include:   change  destination,
stop at that rest room or restaurant, go slow, go at emergency speed.

	2.  The user need not be a driver and need not even accompany
the car.      This would permit children, old people, and  the  blind
greater personal freedom.   It also permits a husband to be driven to
work, then send the car home for his wife's use, and permits  her  to
send it back for him at the end of the day.   The car can be sent for
servicing or to a store where a telephone-ordered  purchase  will  be
put  in  it.     If there is a suitable telephone system, the car can
deliver a user to a place where there is  no  parking,  go  away  and
park,  and  return when summoned.  Thus, the system is to have almost
all of the capabilities of a chauffeur.

	3.   In contrast to a system based on a central computer, the
proposed  system  will  be  of advantage to the first person who buys
one, whether anyone else has it or not. It will require no change  in
existing  roads, but will be able to take orders from traffic control
computers when they are installed.      When  freeway  lanes  can  be
dedicated to computer controlled cars they will multiply the capacity
of existing freeways by permitting 80 mile per hour  bumper-to-bumper
traffic  with greater safety than we have at present.       Since the
system is a product and  not  a  public  utility,  competition  among
suppliers will be possible.

	4.    A key goal is to achieve greater safety than we have at
present.  A five-fold reduction in fatalities is probably required to
make  the  system  acceptable.   Much better is possible since humans
really  are  rather  bad  drivers,  but  complete  safety  cannot  be
guaranteed.

	Now  we shall consider the problems that have to be solved in
order to realize the system.

	1.  Performance of  the  computer,  cameras,  and  associated
electronics.
	Present computers seem to be fast enough and to  have  enough
memory  for  the job.   However, commercial computers of the required
performance are too big.  We envisage that a computer  of  about  the
power  of  the  Digital Equipment PDP-10 will be required.   Military
versions of similar computers have volumes of one or two cubic  feet,
but  the  requirements  for  memory  and  secondary  storage would be
difficult to meet in a reasonable volume at present.    However,  the
development  of more compact computers and other electronic circuitry
is proceeding at a rate that makes achieving the required compactness
not  the  pacing  item.      Some improvements in the performance and
compactness of television cameras is also required, but it is not yet
clear what these requirements are.

	2. Cost of the computer and other electronics.
	At present prices, a computer capable of  controlling  a  car
but  containable only in a large van would cost $400,000 to $800,000.
A few thousand dollars worth of other electronics would be  required.
Ten  years  should  bring  the  cost down by a factor of ten.    Mass
production would give another factor of three.  This would permit the
system  to  be available as a luxury item.  Another five to ten years
might be required before computer control would only double the price
of the car.  These estimates must be regarded as guesses.

	3. Reliability of the computer and other electronics.
	We  can  attempt  to  compute  the  required  reliability  by
demanding  that  present traffic fatalities be reduced to a fifth the
present number, i.e.  to 10,000 per year, and by allocating only half
of  these  fatalities  to unreliability of the electronics.      This
further depends on the fraction of failures  that  lead  to  fatality
which  can  be kept quite low by having the computer check its health
and that of the electronics  every  tenth  of  a  second,  giving  it
programs for dealing with partial failures, and providing a "dead man
switch" for stopping the car if the computer  fails  to  reassure  it
every  tenth  second.  There are many possibilities in this direction
and the expenditure of much cleverness is called for.  The reader  is
advised  against using his unaided intuition to estimate the results.
Nevertheless, present computer failure rates would not be  acceptable
even   if   they   never  led  to  accident  simply  because  of  the
inconvenience.      We  estimate  that  an  improvement  of  1000  in
mean-time-between-failures  is  required.     Rapid progress is being
made in this field, and we expect that ten to  fifteen  years  normal
progress of the computer field will give the required result.

	4.   Performance of the driving programs.
	Developing  the  required  computer  programs  is  the   most
difficult  of  the  required tasks; it will probably take the longest
time; and the amount of time required is very difficult  to  predict.
Work  on  computer  control  of  vehicles has started at the Stanford
University Artificial Intelligence Project. An  experimental  vehicle
has  been  equipped  with  a  television  camera and connected to the
computer with a two-way TV and radio link.     A  simple  program  to
guide the vehicle to follow a white line like that in a road has been
successfully checked out, and programs for determining the course  of
the  road and detecting cars and other obstacles are being developed.
However, before computer controlled cars  become  a  reality  a  much
larger scale effort will have to be made.

	The  nature  and extent of this effort are not easy to forsee
yet.    We are far from having exhausted  the  possibilities  of  our
present equipment, but eventually the radio link to the computer will
have to be replaced by a computer  in  the  vehicle,  and  television
equipment  capable  of  seeing better into shadows in the presence of
bright areas will be required.  We need to be able to  identify  many
different  types of objects on the road such as:   persons, vehicles,
animals, traffic police, shadows, pieces of paper,  cardboard  boxes,
objects  that  have  dropped  from  vehicles, traffic signs and other
signals, intersections, house numbers, and other information required
for  navigation.    It  will  have  to  be  equipped with programs to
recognize and deal with a variety of emergency conditions.   It  will
surely  be  possible  to make it better at this than humans since its
attention won't lapse, it can sense the mechanical condition  of  the
car  continuously,  and  it can look to the side, underneath the car,
and behind every second.

	The most intricate  single  problem  is  the  visual  pattern
recognition.

	5. Testing.
	After the required performance is demonstrated and before the
system  can  be  trusted  without a human driver an extensive testing
program is required.   To demonstrate that the system is  five  times
safer  than a human driver approximately 25,000 automobile years will
be required. This might be reduced somewhat by concentrating  testing
on  situations in which humans make most of their fatal mistakes, but
we would still need to be sure that situations in which  the  program
made fatal blunders peculiar to the computer system were rare enough.
Developments in the mathematical theory  of  computation  may  permit
getting  rid of ordinary programming errors and proving that they are
absent, but possible inadequacies in the  algorithms  themselves  can
only be obviated by testing.

	6.  Public acceptance.
	Automobiles without  qualified  human  drivers  will  require
changes  in the law.  Fortunately, testing such systems with a driver
present to take over if necessary does not. Moreover, computer driven
cars will not be able to obey oral instructions from policemen , so a
digital system will have to be developed.  A  general  resistance  to
technological  innovation  on  the  part of the literary culture will
have to be overcome, but it seems to me that after the test phase the
advantages will be clear enough so that this will not be difficult.

	7. Support for research and development.
	The  development  of  computer  controlled  cars  will   cost
hundreds  of  milliions  of  dollars.   A computer program capable of
reliably taking care of all  the  contingencies  that  can  arise  in
driving a car will have to be more complex than any ever written, and
adequate testing will require a complex  organization.   Fortunately,
The  commitment of large amounts of money will be required only after
spectacular   though   unreliable   performance   will   have    been
demonstrated.  So far as I know, the Stanford Artificial Intelligence
Project is the only organization now working on computer control of a
vehicle  using vision.  This work is part of a basic research project
on artificial intelligence supported by the  Department  of  Defense.
Even  at  the present stage of the work, other projects are needed to
secure  an  adequate  diversity  of  approach.    While  considerable
additional  progress will certainly be made with the present support,
even a prototype will require more money than is now available.

	Fortunately, this problem is within the jurisdiction  of  the
Department  of  Transportation.    The  automobile  companies and the
computer companies also might be expected to  help,  but  their  past
record  of  seeing beyond the ends of their noses is not encouraging.
Because the programming is the pacing item, more support at this time
will  hasten  the  day when computer control of cars is achieved, but
the possibilities will be much more obvious in five  years  with  the
advances  in  hardware  and programming that are already taking place
for other reasons.

	Finally, we would like to deal with some arguments that might
be  raised  against  supporting research aimed at computer-controlled
cars:

	1.   Cars must be done away with because they  produce  smog,
require too much space, and use up too much natural resources.
	We believe the smog devices will eventually be made  to  work
well,  or if not, another form of propulsion can be found.   Computer
controlled cars will require less space than equivalent present  cars
because  they can go faster and closer together on streets, roads and
freeways, because they can park at a distance from a place where they
discharge passengers, and because a computer driven car can be shared
more easily than a conventional car.  If hydrocarbon  fuel  runs  out
and is still required for cars, then with nuclear energy, the burning
reaction can be driven backwards and  fuel  synthesized  from  carbon
dioxide and water.

	2. A simpler scheme of automatic control is preferable.
	The buried cable and other simple  schemes  do  not  increase
human  freedom  and  convenience.     They  only permit us to use the
freeways a bit more efficiently.    Because  of  their  inability  to
detect  dogs,  children,  potholes, and objects that have fallen from
trucks they may require unrealizable control of access to the highway
in order to achieve safety.

	3.    Some form of automated mass transportation is obviously
better.
	The automobile can go point to point in areas of both low and
high density.   We believe that these advantages should not and  will
not  voluntarily  be  given up.  We favor the development of improved
mass transportation, but predict that the automobile will be given up
only  for  something  that  works  better  in  all  ways  such as an
individual computer controlled flying machine  capable  of  point  to
point transportation.