Evening star., 1925-07-19

These data come from the perform
ance Of one Government test car.
Automobiles with better brakes could
travel at the hazardous points safely
at greater speeds. Cars with poorer
brakes would have TO reduce their
speeds lower than the above limits.
The Government has recently con
Quoted experiments which suggest the
| idea of developing a standardized
group of tests which will measure
the proficiency of the ordinary auto
mobile driver. The purpose Of these
tests. made by H. H. Allen, is TO
enable the authorities to separate the
seed from the weeds, the chaff from
the wheat. The prospective driver
who passes these tests and is grant.
ed an operators permit will be adept
and skillful. Persons incompetent to
drive automobiles will be caught
among the driftwood and denied the
privilege which they covet. The ex
animation recommended by Uncle Sam
features the customary performance
test, driving and reversing the car,
turning around, stopping on ener
gency signal and the like. Impor
tant questions about traffic regulations
| and the rules OF the road are also
asked. The eyesight and hearing of
each candidate are examined. He is
| subjected TO stringent auditory and
visual tests. On all these replies. re
| sponses and reactions the man is
| scored on the basis of 20 as a passing
mark.
| Finally. he is requested to enter the
| drivers seat and to operate a special
| test car which will ascertain definitely
| his mental lag and his reaction TO
| sudden emergencies This particular
car, of standard gear-Shift type, is
| provided with two revolvers which
are mounted securely underneath the
| running board. These pistols shoot
\ bullets of red lead which leave q
| red imprint on the pavement when
| ever one of them is discharged. The
! control trigger of the first revolver
| terminates in a wire which extends
| to the observers seat. The second
| firearm is connected directly with the
| brake pedal so that when the driver
| makes a move to apply his foot brake
| this pistol is discharged. The car is
equipped with a special speed-register-
| ing device which is much more &C
| curate than the average speedometer.
THE driver is instructed TO develop
a speed of 10 miles an hour and
to hold the car exactly at that speed
| until the observer discharges the first
| pistol. Then the driver as rapidly as
| possible is to go through the pro
| cedure of stopping the car. When he
applies the brake the second revolver
| is discharged. The scientists then
measure the distance between the two
red spots on the pavement. The ratio
of this distance to the velocity of the
car in feet per second is known
scientifically as the mental lag or re-
action time of the driver. 1t is a
measuring rule which accurately
Classics his qualifications as a good.
| mediumly good or poor operator.
Each driver undergoes five tests al
| as many different speeds, which range
| from 10 to 80 miles an hour. The re
suits of approximately 300 of these
| tests show that a skillful driver will
have a reaction time of a trihe more
than one-half a second. The most ex-
pert among those tested made average
records of as low as 81 second. while
others required as much as 1.o2
| seconds. The drivers Uncle Sam has
| tried out include a number of George
Washington University and Howard
| University students IS well as a group
! of professional taXicab operators and
| a number of soldiers and officers of the
| Motor Transport Corps of the United
States Army.
| Reaction time is of fundamental i'm
portance in the promotion or curtail
ment of automobile accidents. For
example. driver with a reaction in
| terval of one-half second has a men
| tai lag equivalent to a distance of -
| feet when his car is travelling at a
speed of 80 miles an hour. This means
| that the car covers a space of % feet
during the period from the time when
| the driver decides to put on the brakes
and when he actually applies them.
Naturally. a driver whose reaction
time is one and one-half or two seconds
| correspondingly covers longer
stretch of roadway between the period
| when he realizes the emergency and
| the time when he steps down on the
| brake pedal. Where the driver has a
action time of one-half a second and
| the velocity of his automobile is 80
miles an hour he will bring his car to
a halt in a space of approximately 100
| feet.
| The difference between safety and
| accident is usually represented by the
varying reaction times of different
motorists when confronted by sudden
| emergencies. One man will react
rapidly and avert catastrophe. An
| other, who is of slower mental stim-
| ulus. will react proportionally much
| slower.
| These experimental tests demon
strate the slow and sure" driver more
often than not is the one who fiirts
| with extreme jeopardy in time of un-
| expected eXigency. The old adage might
preferably be scrambled about like an
egg in order to visualize present cir
cumstances in the motoring world. In
revised form, it would run something
| like this, SLOW and unsure; quick and
sure" The age factor up to about
A years is insignificant. but from As
to 65 it is a vital limiting factor. I'm
der such conditions. as a rule, the old
er the driver, the greater his reaction
| time.
No decided variations due to sex or
race have been appreciable in the
tests thus far conducted. Several girl
students from George Washington
| University made as good records as
the male students. Colored students
from Howard University did as well
as the whites. Intelligence, however.
is a most important factor in the de-
termination of what driver will do in
a pinch and how quickly he will do it.
The more intelligent the operator the
more rapidly his reaction to avert i'm
pending accident. Similarly, the
greater the skill of the motorist the
lower is his reaction time.
A development of Ehe future which
Washington automobirlsts are sure TO
shake hands with will take the form
of standardized driving tryouts. They
will constitute the acid test which will
determine the fitness of the prosper
tive operator to drive his motor caA
| within the confines of the District Ons
efficient manner of producing better
and more careful drivers is to make
! the requirements so severe that only