i:X Feedbock - NASA...streamer theory states in essence that the driver perceivegmtion fhn objects...
17
R. Wade Allen and Duane T. McRxer Systems Technology, Inc. IWdthorne . California A ohidation experiinent was conducted to determine the effect of reduced visibility on driver late- (steering) control. The simulator included a real car cab and a single lane road image projected on a screen six feet in front of the driver. Simulated equations of notion controlled apparent car lane position in response to driver steering actions, wind gusts, and mad curvature. Zix drivers experienced a range of visibility conditions at vari- ms speeds with assorted roadmarkirg configurations (mra and gap lengths). lkiver 5escribira ?unctions were ffieasured and detailed pmewtric model fits were detemined. A pursuit model employ-lng a rosd cwvature feedfornard was very effective in explaining driver behavior in following randoaly curving mads. Sampled-datz concepts were also effective in explaining the cmbined effects of reduced visibility and intennittent rosd markings on the drlver's dynamic time delay. The results inaicate the relative importance of various perceptual variables as the visual input to the driver's steering control process i: ci-~nged. Autonobile steering control is a QNlmic task that i s performed by the dri-- in order to establish and/or aaintain the vehicle on a specified path- way in the presence of inpmts such as crosswinds and mdw8y curvature. The motions of an automobile !n response t o steering actions and aerodynamic dis- turbances csn be described in terns of differential equations, transfer func- tions, etc. ( ~ e f . I), and it iz logical to attempt to drxribe the driver in sinilar +ems. In the research described herein the motivation for a Qnamic description and measurment of the driver was twofold: 1) to dstermine and quantify the effect of adverse visibility on driver perception of the cues required for steering control; and 2) to determine those changes in driver behavior that contribute to degraded performance under conditions of reduced visibility. Ar. understanding of these effects may then suggest countermeasures to vehicle .cntrol problems associated with adverse visibility. Given that mad delineation features (e.g., dnshed lines) are detected, the driver's perceptual processes can then extract informetion for vehicle control. Adverse visibility conditions can reduce visual (Xef. 2), and the questior to be considered here i s >aw ree~ced visibility might affect driver perception of vehicle path and subsequent control actions. An abstraction of the driver's p?rcephal task is illustrated in Pig. 1, a perspective viw of a single lane bounded bj dashed lines. With forward motion in a straight line the driver's visual scew appars to e - d Pran a perspecti- vanishing point at infinity. Theories h v e been advanced for a focus or center of expansion perception of motion (Ref. 3). On straight roads the renter of expnsion is the only point in the visual field that is apprently stationary, and it would provlcle n direct cue for the car's path angle. Thus, when forward view i s reduced by adverse visibility, direct per- ception of path angle i s denied the driver according to the focus of expmsion theory. This theory has some problw, hwever. As Gordon (Ref. L) wtes, for curved paths the center of expansion lies at the center of cumture, vhich i s at right angles to the path of the vehicle. l'urthermore, Wlmer (Ref. 5) Horizon and Driver Vanishing Po~ot Eye Height lft) I2 tt ~ane With 7' k:.‘-- '4tm ~o;nt:~oss~ble i:"X Feedbock for Driver 60 ft --- I---, ! Steering Control Cor/Driver Line of Sm Plgure 1. Driver's Perspective View of a Single Delineated htt Illustrating an Aim h i n t Control IsW https://ntrs.nasa.gov/search.jsp?R=19790009322 2020-05-23T23:18:01+00:00Z
Transcript of i:X Feedbock - NASA...streamer theory states in essence that the driver perceivegmtion fhn objects...
R. Wade A
llen
and D
uane
T.
McR
xer
Syst
ems
Tec
hnolo
gy,
Inc.
IW
dtho
rne . C
ali
forn
ia
A
oh
ida
tio
n e
xper
iinen
t w
as
con
du
cted
to
det
erm
ine
the
eff
ec
t o
f re
du
ced
v
isib
ilit
y o
n d
riv
er
late
- (s
tee
rin
g)
co
ntr
ol.
T
he
sim
ula
tor
incl
ud
ed a
re
al
ca
r ca
b a
nd a
sin
gle
la
ne
ro
ad
imag
e p
roje
cte
d o
n a
scre
en s
ix f
ee
t in
fr
on
t of
the
dri
ve
r.
Sim
ula
ted
eq
uat
ion
s of
no
tio
n c
on
tro
lle
d a
pp
aren
t c
ar
lan
e p
osi
tio
n
in r
esp
on
se t
o d
riv
er
ste
eri
ng
ac
tio
ns,
win
d g
ust
s,
and
ma
d
curv
atu
re.
Zix
dri
ve
rs e
xp
erie
nce
d a
ran
ge
of
vis
ibil
ity
co
nd
itio
ns
at
va
ri-
ms
sp
eed
s w
ith
ass
ort
ed
road
mar
kir
g
con
fig
ura
tio
ns
(mra
and g
ap l
en
gth
s).
lkiv
er
5e
scri
bir
a ?
un
ctio
ns
wer
e ff
ieas
ure
d a
nd d
eta
ile
d p
me
wtr
ic m
odel
fi
ts w
ere
det
emin
ed.
A p
urs
uit
m
odel
em
ploy
-lng
a ro
sd c
wv
atu
re f
eed
forn
ard
w
as
ver
y e
ffe
cti
ve
in
ex
pla
inin
g d
riv
er
beh
avio
r in
fo
llo
win
g randoaly c
urv
ing
m
ads.
S
ample
d-d
atz
con
cep
ts w
ere
als
o e
ffe
cti
ve
in
ex
pla
inin
g t
he
cm
bin
ed
eff
ec
ts o
f re
du
ced
vis
ibil
ity
and
in
ten
nit
ten
t ro
sd
mar
kin
gs
on t
he
drl
ve
r's
dyna
mic
tim
e d
elay
. T
he r
esu
lts
ina
ica
te t
he
rela
tiv
e i
mport
ance
o
f v
ario
us
per
cep
tual
v
ari
ab
les
as
the
v
isu
al
inp
ut
to t
he
dri
ve
r's
ste
eri
ng
co
ntr
ol
pro
cess
i:
ci-~
ng
ed.
Au
ton
ob
ile
ste
eri
ng
co
ntr
ol
is a Q
Nlm
ic
task
th
at
is
per
form
ed
by
the
dri-
- in
ord
er
to e
sta
bli
sh a
nd
/or
aa
inta
in t
he
ve
hic
le o
n a
spe
cif
ied
pat
h-
way
in
th
e p
rese
nce
of
inpm
ts s
uch
as c
ross
win
ds
and
md
w8
y c
urv
atu
re.
The
moti
ons
of
an a
uto
mo
bil
e !n
re
spo
nse
to
ste
eri
ng
ac
tio
ns
and a
erodynam
ic d
is-
turb
ance
s cs
n be
d
escr
ibed
in
te
rns
of
dif
fere
nti
al
equ
atio
ns,
tr
an
sfe
r fu
nc-
tio
ns,
e
tc.
(~
ef
. I)
, an
d i
t i
z l
og
ica
l to
att
emp
t to
drx
rib
e t
he
dri
ve
r in
sin
ila
r +
em
s.
In t
he
res
earc
h d
escr
ibed
her
ein
th
e m
oti
vat
ion
fo
r a
Qnam
ic
de
scri
pti
on
and
mea
surm
ent
of
the
dri
ve
r w
as
two
fold
: 1
) t
o d
ster
min
e an
d q
ua
nti
fy t
he
eff
ec
t o
f ad
ver
se v
isib
ilit
y o
n d
riv
er
per
cep
tio
n o
f th
e c
ues
req
uir
ed f
or
ste
eri
ng
co
ntr
ol;
an
d 2
) to
det
erm
ine
tho
se c
han
ges
in
dri
ve
r b
ehav
ior
tha
t
co
ntr
ibu
te t
o d
egra
ded
per
form
ance
under
co
nd
itio
ns
of
red
uce
d v
isib
ilit
y.
Ar.
un
der
stan
din
g o
f th
ese
eff
ec
ts m
ay t
hen
su
gg
est
cou
nte
rmea
sure
s to
ve
hic
le
.cn
tro
l pro
ble
ms
ass
oc
iate
d w
ith
ad
ver
se v
isib
ilit
y.
Giv
en t
ha
t m
ad
de
lin
ea
tio
n f
ea
ture
s (e
.g.,
dnsh
ed l
ine
s) are
det
ecte
d,
the
dri
ve
r's
pe
rce
ptu
al
pro
cess
es
can t
hen
ex
tra
ct
info
rmet
ion
fo
r v
eh
icle
con
tro
l.
Adver
se v
isib
ilit
y c
on
dit
ion
s ca
n r
educe
v
isu
al
(Xef
. 2),
and t
he
qu
est
ior
to b
e co
nsi
der
ed h
ere
is >
aw r
ee
~c
ed
vis
ibil
ity
mig
ht
aff
ec
t d
riv
er
per
cep
tio
n o
f v
ehic
le p
ath
and s
ub
seq
uen
t c
on
tro
l a
cti
on
s.
An
ab
stra
cti
on
of
the
dri
ve
r's
p?
rce
ph
al
task
is
ill
ustr
ate
d i
n Pig.
1,
a p
ers
pe
cti
ve
viw
of a si
ng
le l
an
e b
ound
ed bj
das
hed
lin
es.
W
ith
forw
ard
moti
on i
n a
st
raig
ht
lin
e t
he
dri
ve
r's
vis
ua
l sc
ew
ap
pars
to
e-d Pran
a p
ersp
ecti
- v
anis
hin
g p
oin
t a
t in
fin
ity
. T
heo
ries
h
ve
bee
n a
dvan
ced f
or
a fo
cus
or
cen
ter
of
exp
ansi
on
per
cep
tio
n o
f m
oti
on
(Ref
. 3
).
On s
tra
igh
t
roads
the
re
nte
r of
ex
pn
sio
n i
s t
he
on
ly p
oin
t in
th
e v
isu
al
fie
ld t
ha
t is
ap
pre
ntl
y s
tati
on
ary
, an
d i
t w
ould
pro
vlc
le n
dir
ec
t cu
e fo
r th
e c
ar'
s p
ath
ang
le.
Thus,
whe
n fo
rwar
d
view
is
red
uce
d b
y ad
ver
se v
isib
ilit
y,
dir
ec
t p
er-
cep
tio
n o
f p
ath
an
gle
is
den
ied
th
e d
riv
er
acco
rdin
g t
o t
he
fo
cus
of
exp
msi
on
theo
ry.
Th
is t
heo
ry has
som
e p
ro
blw
, h
wev
er.
As
Gor
don
(Ref
. L) w
tes
,
for
curv
ed p
ath
s th
e c
en
ter
of
exp
ansi
on
lie
s a
t th
e c
en
ter
of
cu
mtu
re,
vh
ich
is
at
rig
ht
ang
les to t
he
pa
th o
f th
e v
ehic
le.
l'urt
her
mo
re,
Wlm
er
(Ref
. 5
)
Hor
izon
and
Dri
ver
Van
ishi
ng P
o~o
t E
ye H
eigh
t lf
t)
I2 tt
~a
ne
W
ith
7'
k:.‘-- '4
tm
~o
;nt:
~o
ss~
ble
i:"X
Fe
edbo
ck f
or D
river
60 f
t ---
I--
-, !
Ste
erin
g C
ontro
l
Cor
/Driv
er L
ine
of Sm
Plg
ure
1.
D
riv
er'
s P
ersp
ecti
ve
Vie
w
of
a S
ing
le D
elin
eate
d
htt
Il
lustr
ati
ng
an
Aim
h
in
t C
on
tro
l I
sW
https://ntrs.nasa.gov/search.jsp?R=19790009322 2020-05-23T23:18:01+00:00Z
has
fo
und t
ha
t th
e c
ente
r o
f ex
pan
sio
n i
n v
ism
l fi
eld
s ex
pan
din
g a
t v
ari-
ous
con
stan
t ra
tes
of
expan
sion can o
r& be p
erce
ived
wit
hin
1
6 deg
rees
of
vis
ua
l a
~z
le, w
hich
is
mc
h t
oo
co
arse
fo
r v
ehic
ula
r co
ntr
ol.
In a
pe
rsp
ec
tiv
e m
otio
rl f
ield
che
st
rem
.ers
th
emse
lves
pla
y a
mre
im
por-
tan
t ro
le i
n t
he
vie
ws
of
Cal
ver
t (R
ef.
5),
rh
o e
mphas
ized
th
eir
mle
in
bo
th
dir
ec
tio
na
l an
d l
on
git
ud
ina
l c
on
tro
l o
f a
irc
raft
on
the
fin
al
app
roac
h,
and
Gor
don
(Ref
. 4
),
who
co
nsi
der
ed t
err
es
tria
l v
ehic
les.
T
he
stre
amer
th
eory
sta
tes i
n e
ssen
ce t
ha
t th
e d
riv
er
pe
rce
ive
gm
tio
n f
hn
obje
cts
in
th
e v
isu
al
fie
ld s
tlea
min
g a
cro
ss h
is fi
eld
of
view
. A
lth
ot~
gh
the
str
eam
ers
eman
ate fmm
the
cen
ter
of
ex
pa
sio
n, Gordon b
elie
ves
th
at it
is
th
e st
ream
ers
them
selv
es,
part
icu
larl
y t
ho
se p
rov
ided
by
road
way
bo
un
dar
ies
and l
an
e m
arkin
gs,
th
at
ud
erl
ie t
he
dir
ec
tio
na
l cu
e ra
the
r th
an t
he
ce
nte
r o
f ex
pan
sion.
He
no
tes
the
t a
ll p
art
s o
f th
e v
isu
al
fie
ld,
road
bo
rder
s,
and
lan
e nn
irlr
ers
mov
e w
!wn
the
wh
eel
is t
urn
ed b
ut
no 0
r.e
pa
rt i
s e
sse
nti
al
for
tra
ck
ing
, an
d t
ha
t th
e
?ri
ve
r re
spo
nd
s to
a t
ota
l si
tua
tio
n
(a C
iiS
talt
co
nce
pt)
, n
ot
to i
sola
ted
or
rank
ed
cues
. S
trea
mer
per
cep
tio
n
sho
uld
IE
fair
ly r
ob
ust
in
th
e f
ace
of
red
uce
d v
isib
ilit
y,
alth
ou
gh
ad-r
erse
vL
sib
llit
y (
i.e.
, ra
in,
fog
) w
ou
ld e
lim
i-
r
na
te m
ar*
sub
tle
cue3
(e
-g.,
ro
ad
mu
gh
ess
, ed
ge
tex
ture
), p
art
icu
larl
y t
ho
se
m
C
av
ail
ab
le o
uts
ide
fo
vea
l v
isio
n w
here
co
ntr
nst
se
nsi
tiv
ity
ana
ac
uit
y d
egra
de
(Ref
. 7)
.
Co
ntr
ol
theory
a
na
lysi
s az
d r
esea
rch
in
to l
and
veh
icie
ste
eri
ng
co
ntr
ol
have i
de
nti
fie
d c
ues
th
at
mus
t be
per
ceiv
ed e
ith
er
ex
pli
cit
ly o
r im
pli
cit
ly
in o
rde
r to
giv
e g
d,
sta
ble
per
form
ance
. T
he
ca
r's
po
siti
on
re
lati
ve
to
the
de
lin
ea
ted
pa
th i
s t
he
mos
t o
bv
iou
s o
f tn
ese.
V
ario
us
stu
die
s hav
e a
lso
da
ms
tra
ted
th
at
hea
din
g o
r p
ath
ar4
le i
s e
sse
nti
al
to a
chie
vin
g st
ab
le c
on-
tro
l (a
s re
vie
wed
in
Ref
. @
).
Thus,
p
rop
rly
ver
gh
ted
can
ponen
ts
pro
po
rtio
na
l
to L
ate
ral
po
siti
on
an
d hea
din
g m
ust
be
pre
se7.t
in
th
e d
riv
er'
s st
ee
rin
g w
hee
l
de
fle
cti
on
if
th
e c
ar'
s p
ath
is
to
be
reg
ult
ted
in
th
e l
ane.
One
in
tuit
ive
ly a
ms
lin
g m
odel
fo
r d
riv
er
late
ral
co
ntr
ol
inv
olv
es st
ee
r-
ing
in
pu
ts b
ased
on
ar aim p
oin
t down
the
ro
ad as
illu
str
ate
d i
n F
ig.
1.
The
aim
po
int
ang
le i
s o
ne w
ay to c
mb
ine
kte
ra
l p
osi
tio
n a
nd p
revie
w-r
ange-
wei
gh
tel
hea
din
g i
nto
a
sin
gle
con'.r
ol
qu
anti
ty.
The
dy
nam
ics
of
this
sim
ple
co
ntm
l m
odel
, am
ong
oth
ers
, ta
w
teen
an
aly
zed
pre
vio
usl
y
(Ref
. 9
).
For
an
*
aim
po
int
at
a d
ista
nc
e,
xa
, a
look-a
hee
d
or
pre
vie
w
tim
e co
nst
ant
de
pe
de
nt
on
veh
icle
sp
eed
, U
o, ca
n be
d
efin
ed a
s f
oll
ow
s:
McL
ean
(Ref
. 1
0)
has
re
vie
wed
a r
imb
er o
f d
riv
ing
va
ria
tio
ns
in r
est
ric
ted
fo
rwar
d v
iew
and v
ehic
le
tim
s (
Ta)
of
2 s
ec
or
gre
ate
r.
The
re
sult
s w
ere
and i
t w
ould
be
dif
fic
ult
to d
ecid
e on
an a
vera
ge
con
stan
t.
exp
erim
ents
involving
0
speed w
hic
h f
ound p
rerr
iev
qu
ite
va
ria
ble
, h
arev
er,
or
typ
ica
l p
rev
iw t
h
If
the
re i
s a
pre
fen
ed
lo
ok
-sh
ead
dis
tan
ce
or
tim
e co
nst
ant,
th
en
restr
icte
d v
isu
al
ran
ge
due
toa
dv
ers
e v
isib
ilit
y c
ou
ld i
nte
rfe
re w
ith
th
is
cue,
an
d v
isu
al
ran
ges
sb
ort
er
than
th
e p
refe
rre
d look-ahead d
istM
ce
vo
uld
be
exp
ecte
d t
o d
ete
rio
rate
per
form
ance
. L
ane
po
siti
on
and heading
cues
do
no
t t.
eces
sari
ly
have
to
be
per
ceiv
ed a
t a
can
bin
ed a
im p
int,
b
arev
er.
Ref
erri
ng
ag
ain
to
F&. 1
, si
mp
le g
eom
etri
c a
na
lysi
s sh
ows
tha
t fo
r sm
nll
ang
les
the
ca
r's h
ead
ing an
gle
dev
iati
on
s w
ith
re
spe
ct
to t
he
la
ne
ap
pea
r
as
ho
riz
on
tal
tra
nsl
ati
ofi
s o
f th
e v
isu
al
scen
e.
Fur
ca
r la
tera
l p
osi
tio
n
de
via
tio
ns
wit
h r
esp
ec
t to
th
e l
ane
th,?
lpad ap
pea
rs to r
ota
te a
bo
ut
its
va
nis
hir
a p
oin
t a
t th
e h
ori
zon
. T
hus
hea
dix
g an
d l
ate
ral
po
siti
on
s are
sep
ara
tely
av
ail
ab
le hpm
the
pe
rsp
ec
tiv
e v
iew
if
a su
ffic
ien
t se
gg
ent
of
this
vie
w
is
vis
ible
.
To gain fu
rth
er
insi
gh
t in
to d
riv
er
per
cep
tual
req
uir
emm
ts,
con
sid
er
the
de
tail
ed
dri
ver
/veh
icle
sy
stem
dyn
amic
mod
el
illu
stra
ted
ln fig.
2. &rc
the
ve
hic
le n
mde
l g
ive
s hea
din
g a
ng
le a
nd l
ate
ral
lane d
evia
tio
ns
($ a
nd
y) .
in r
esp
on
se t
o d
riv
er
ste
eri
ng
oom
nand
s (b). The d
riv
er
dev
elo
ps
ste
eri
ng
c-nd
s k
se
d o
n h
is p
erce
pti
on
of
lan
e p
osi
tio
n a
nd h
ead
ing
an
gle
err
ors
,
plu
s an
ad
dit
ion
al
term
pm
po
rtio
na
l t
o p
erce
ived
mad c
urv
atu
re.
Tbc
p a
nd
* prc
ep
tio
ns are b
asi
ca
lly
in
vo
lved
in
reg
ula
tio
n-o
nly
dri
ve
r co
ntr
ol,
w
hic
h
is h
and
led
in
a c
om
pen
sato
ry f
ash
ion
. The
added
cu
rvat
ure
tern i
s a
prr
suit
or
feed
fo-
elem
ent
nee
ded
to
acco
un
t fo
r d
riv
er
beh
avio
r on c
urv
ed r
oad
s.
It b
asi
ca
lly
ass
Mes
th
e d
riv
er
il-s
ert
s an
open
-loop
ste
eri
ng
whee
l ca
man
d
pm
po
rtio
na
l to p
erce
ived
pa
th c
urv
atu
re.
:me
an
tic
ipa
tio
n or
Mv
er
lead
(TL
) is a
pp
lie
d t
o t
he
se p
erce
pti
on
s to
off
set
ve
hic
le L
ag,
and
a t
ime
del
ay
penalty (T) i
s i
ncu
rred
by
thc
dri
ve
r du
e t
o b
asi
c n
eum
mu
scu
lar
char
acte
r-
isti
cs
an
d p
erc
ep
tua
l p
roce
ssin
g l
oad
. A
fi
na
l co
mpo
nent
of
the
dri
ve
r's
ste
eri
ng
ac
tio
n i
s c
anp
ose
d o
f n
aman
t w
hich
is
bss
ica
lly
no
ise
or
rar.
dm
va
rist
ion
in
th
e d
riv
er'
s o
iltp
ut
un
co
rre
late
d with
pe
rce
ptu
al
inp
nts
.
The
re
gu
lati
on
or
err
or
co
rre
cti
ng
po
rtw
n o
f th
e F
ig.
2 r
aode
l,
inv
olr
-
in8
on
ly l
an
e p
osi
tio
n e
nd
heading e
rro
r fe
edb
nc.
a (y
e an
1 v
e,
resp
ec
tiv
ely
)
hns
bee
n s
haa t
o h
ave good,
sta
ble
co
ntm
l p
rop
ert
ies
(Ref
. 11 )
and t
o b
e
co
nsi
ste
nt
wit
h e
xp
erim
enta
l ae
asu
nm
ents
(R
efa.
$2
sad
12).
T
his
md
e o
f
co
ntr
ol
is t
em
ed
co
mp
ensa
toq
in
tk
t th
e d
riv
er
is "
can
pen
sati
ng
" fo
r d
is-
turb
nn
ca c
ause
d e
rro
rs.
In th c
ase
of
a w
ind
dis
turb
ance
th
e d
riv
er
ks
no
per
cep
tio
n o
r p
rev
iew
of
the
dis
turb
ance
, an
d m
ust
va
it f
or
the
dis
turb
ance
to a
ffe
ct
the
ve
hic
le's
m
oti
on
b
efo
re responding.
Whe
n fo
llo
win
g a
cu
rvin
g r
oad
(a
pt
h e
orm
uurd
) w
j'h
suff
icie
nt
vfs
ual
ran
ge,
th
e 3
riv
er has
the
op
po
rtu
nit
y t
o p
revi
er 1
r
arit
ic1p
nt.e
the
de
sire
d
pat
h.
Wit
h a
v
isu
al
segm
ent
larg
e e
nough to
-it
adeq
uat
e p
erce
pti
on
of
tbe
road
's c'-tun,
tbe
dri
ve
r ca
n a
chL
eve
a p
rsu
it m
ode
of
co
ntm
l
beh
avio
r an
d v
ery
n
ea
rly
du
pli
ca
te t
ba
m&
lr
d
pat
h.
This i
s s
ibp
ly a
cmm
-
pli
she
d b
y the
dri
ve
r b
ecau
ae
in s
tead
y s
tate
th
e c
urv
ed p
ath
fa
lla
nd
by
a
ca
r is
n
ea
rly
dir
ec
tly
pra
po
rtio
na
l to
irm
t w
heel
an
gle
(R
ef.
131,
an
d t
he
Veh
icle
la
gs are
wel
l-le
arn
ed
and
can
be
an
tic
ipa
ted
. T
hw
, th
e d
riv
er
wnly
st
eers
wit
h a
cti
on
s d
ire
ctl
y p
rqo
rtio
ml
to p
erce
ived
ro
ad N
N~
-
ture
, su
ffic
ien
tly
ad
van
ced
in
tim
e to
off
se
t v
eh
icle
la
g.
Dis
rup
tfa
of
the
curv
atu
re c
ue
wil
l clew
pu
su
it p
erfo
~rm
ancc
, ho
ver
er,
whi
ch is
r
po
ssib
ilit
y w
ith
nu
iud
s c
crb
ina
tio
as
of
adv
erse
vis
ibil
ity
an
d d
+li
nc
ati
an
as
dis
cuss
ed p
rev
iou
sly
.
Co
nsi
der
nar
th
e c
on
tro
l an
d p
erfo
-ce
imp
lica
tio
ns
of
con
pm
mto
ry
and
pu
it
beh
avio
r.
Giv
en
mod
el s
t~
ct
un
of
F
ig.
2 and n&&
dri
ve
r
pn
ma
ete
rs
ob
tain
ed i
n t
his
stu
Q
un
der
goo
d v
isib
ilit
y a
t 30
rrp
h,
we
hav
e
anal
yze
d t
he
by
na
dc
im
pli
ca
tio
ns
of
curt
ratu
re p
erce
pti
oa.
R
eie
rria
g to
Fig
. 2,
co
nsi
der
th
e d
riv
er/
ve
hic
le
syst
em r
eq
on
se d
ue
to
a c
cam
md path
inp
ut.
m
e c
cx
rrir
de
l p
ath
ca
ur,,?
s ax
? e
qu
ivsl
en
t h
ex
din
g r
ate
i
np
t,
r:,
to
be
ap
pli
ed
to
th
e
syst
em.
Dri
ve
r it
ee
rir*
x
ti
on
sh
ou
ld t
he
n
cre
ate
ves-
?le
)%w
ra
tes
, r.
wti
cn
are
ne
nrl
y
2~
~x
1
to
th
e
.am
&?.
ded
he
ad
ing
ra
te so
a;
to ~
iv
e
a
sd
l t~
ea
dir
y, r
ate
err
or,
r,
, w
hic
h
is
th
e d
iffe
ren
ce
bet
wee
n
tho
xm
na
r~
~
inp
ut
and
th
z v
eh
irle
's
no
tio
n.
% il
lus
trn
te t
he
r.o
ten
tio
1
imp
m~
rne
nt i
n p
rfo
rma
nc
e b
etw
een
p
urs
uit
xnd
ccm
pens
ator
:.p
Iriv
ing
we
csn
c
as
ide
r t
he
de
scri
b!r
e
Pm
cti
on
re
lati
ng
he
din
g r
ate
er
mr
, r,
, t
o h
ead
ing
=
tz
inru
t co
m?l
an.l
, rc
. F
igw
e
sho
rs
b1
e p
lots
o
f th
is i
riv
er,
've
hir
lo
syst
em
mt
io
a: th
e c
urv
atu
re p
?rc
ep
tio
n
pa
rme
ter
(dri
ve
r's
"p
urs
uit
ga
inn
), f
*,
is ir
.:re
ased
. T
he
com
pen
sato
ry
~m
ss
lin
r cr
.~
(KR~ = 0) i
s h
azed
o
n a
re
pre
sen
tati
ve
se
t o
f d
riv
er/
ve
hic
le
lata
, 113.
the
oth
er
cu
rve
s s
imp
ly
ind
ica
te t
he
eff
ec
t o
f lr
e/r
c( w
hen
the
ad
dit
ion
al
dri
ve
r c
on
tro
l p
ath
way
re
pre
en
ted
by
F*C
iz
add
efeC
. A
t l
m f
re-
au
en
cie
s th
e i
es
-rib
ing
fu
nc
tio
n a
qli
tud
r s
how
s th
at
er
mr
s are
les
s t
ha
n
the
or'
.1
in
pit
, w
hil
e a
t v
ery
hi&
fr
eji
len
cie
s th
ey
?,a
y be
saw
wh
at
gr,
' . .
Ro
t?
in p
art
icu
lar
tha
t fo
r th
e j
rle
al
no
-lag
v
eh
icle
s
li op
tim
um
fig
me
:.
Eff
ec
ts o
f V
ari
ati
on
s in
th
e C
urv
atu
re P
erc
ep
tio
n G
ain
on
th
e H
ea
dir
a E
rrn
r R
ate
to
He
ali
ng
Fa
te I
np
ut
Tn
rs
fe
r m
ct
io
n
vz
lue
' o
f IQ
C/f
- 1, e
rm
rs
in
th
e f
req
ue
nc
y
reg
ion
of
0.5-
1.0
rad
/se
c
giv
e
a
red
uc
tio
n
AC
~
err
or : f
ab
ut
15
dB o
r a
fa
cto
r cf g
rea
ter
than
5
tim
es:
At
any
giv
en
fr
eq
ue
nc
y,
lan
e d
iqe
rsio
ns
are
dir
ec
tly
pro
po
rtio
na
l to
hea
din
g
rate
err
ors
and t
hu
s th
e c
drv
atu
re p
rce
pti
on
in
th
e a
bo
ve
fre
qu
en
cy
re
gio
n
vo
uld
re
3u
ce
la
ne
dis
pe
rsio
ns
by
mor
e th
an
a f
ac
tor
of
5.
The
F
ig.
. m
ade1
can
se
rve
as
th
e b
esi
s fo
r sa
ce
ob
serv
ati
on
s a
bo
ut
driver
vis
ua
l p
erc
ep
tio
n r
eq
uir
em
mts
an
d p
ote
nti
al
eff
ec
ts o
f d
eg
rad
ed
vis
ibil
ity
.
Zo
nsi
de
r f
irs
t th
e d
riv
er'
s
use
of
the
ah
po
int
co
nc
ep
t il
lus
tnte
d i
n E
lg.
1.
Her
* re
dw
tio
ns
in
vis
ua
l ra
nge
un
de
r a
dv
ers
e
vis
ibil
ity
co
nd
itio
ns
.an
eli
mi-
na
te
the
cu
es
req
uir
ed
to
dir
ec
tly
pe
rce
ive
th
e a
im p
oin
t.
In t
his
ch
se t
he
dri
ve
r ca
n
ex
tra
po
late
frao
the
av
aii
ab
le c
ue
s o
r,
alt
ern
ati
ve
ly,
sep
ars
tely
pe
rce
ive
la
ter
al
and
h
ea
din
g
err
or
de
via
tio
ns.
In
e
ith
er
cs
se
, h
awev
er,
the
dri
ve
r is
fa
ce
d w
ith
an
in
rre
ase
d p
erc
ep
tua
l lo
ad
. P
nst
re
sea
rch
has
sho
vn
tha
t in
cre
ase
d p
erc
ep
tua
l lc
ad
le
ad
s t
o i
nc
rea
ses
in ti*
d
ela
y (
7)
an
d n
ois
e
or
re
mr~
an
t (R
efa.
1'
and
I:
). T
hes
e e
ffe
cts
sh
ou
ld
inc
rea
se w
ith
de
cre
ase
d
vis
ua
l ra
ng
e.
Whe
n re
du
ce
d v
isu
al
ran
ge
in
terf
ere
s w
ith
dir
ec
t p
erce
pth
a o
f tk
aim
po
int,
th
e l
an
e d
el.
ine
ati
on
co
nfi
gu
rati
on
th
en
sb
ou
ld b
ecom
e an
irp
ort
ant
fac
tor.
C
on
sid
er
fig
. 1
wit
h r
es
tric
ted
pre
rleu
. The d
river
needs a
dt
pt
e
info
mu
tio
n t
o p
rc
riv
e e
e, y
e,
and
ra
rd c
urv
atu
re.
If
se-+
em1 de
lin
ea
' 'on
ele
me
nts
arr
vis
ible
, o
r s
ing
le e
lcre
nts
are o
f s
uff
icie
nt
len
gth
, C
hc
e v
ari-
ab
les
sho
uld
be
dir
ectl
y p
erc
eiv
ab
le.
If e
lem
en
t le
ng
th i
s reduced,
ba
riv
er,
so
th
at
pa
th d
ire
cti
on
is n
&
rea
dil
y in
dic
ate
d b
y a s
ing
le e
lem
en
t,
tben
tw
o
ca
ap
on
rnts
a
re n
eed
ed t
o d
efi
ne
dr
ec
tio
n and th
ree t
o i
nd
ica
te c
urv
ature
. In
te
rms
of
the
Fig
. 2 model,
a via-
seg
men
t w
hir&
c
on
tsln
s a
t le
ast
thre
e
ele
me
nts
is
nee
ded
fo
r d
ev
elo
ple
nt
of
the
Xpq
fe
ed
fon
mrd
, u
hil
e a
t la
st
two
el-
en
ts
are
nee
ded
fo
r g
e to
be
est
ima
ted
. T
tns
the
dri
ve
r/v
eh
lcle
sy
stem
dm
am
irs
wil
l d
epen
d s
trongly
ar
the
dia
en
sio
ns
of
the
visual
se
mn
t.
As
'For
the
es
se
nti
all
y n
eu
tra
l st
efu
ca
r of this s
tud
y t!k
s
L~
-s
t.a
te
tu
rn radius
is
eq
ua
l ta
the
wh
ee
lba
se d
ivid
ed
by
the
ht
-e
l angle
(Ref
. lJ
), so
th
e c
urv
atu
re p
erc
ep
tio
n g
ain
sh
od
be
eq
un
l t
o +.he
Uu
'S
wh
eelb
ase,
in
th
is c
ase
9.25
feet.
fieu
rn '..
Sh
rrL
ato
r T
est
Cu
nd
itio
r.
Wt
rh
9 ft
mu
ks
and
a R cycle
(Ref
. 1
7).
th
e n
ati
on
al standard r
ec-n
dat
ions
of 15
ft
aa
rks
and
b ft
cy
cle
s (R
ef.
18
).
and a
very
sh
ort
ele
men
t speced
at k0 fi
mea
nt
to
sh
la
te
re
tro
refl
ec
tors
whic
h
rnd
ivid
ua
lly
off
er
no
dir
ec
-
tic
na
l cu
es.
A
-her
v
ari
att
on
was
ap
p1ie
.l to the
ria
t b
orn
dsr
y of t
he
retr
orc
fle
cto
r d
eli
wa
tin
whic
h
inc
luie
d e
ith
er
a s
oli
d,
dot
(re
fle
cto
r) or
bla
nk
(n
o r
igh
t ed
ge
1ir
.s)
co
n*
fglr
ati
on
. A
so
lid
ed
ge
lin
e would p
resu
rab
ly
imp
rove
pe
rfo
n n
nce
w
er
that
vit
h d
ott
ed
ele
me
nts
, w
hil
e t
he
lack of any
edge
lie
e a
t a
ll v
mld
d
egra
de
per
form
an-?
m
de
r ad
ver
ve
vis
ibil
ity
. It
was
imp
rac
tic
al
to rur!
nll
rm
bin
ati
on
s o
f th
e f
ac
tors
sho
wn
in Fig.
5,
so +
h-
cu
nb
inati
on
s ll
ste
d .n T
able
1 wore
se
lec
ted
to
span
th
e W
or
diw
n;i
on
s,
vit
h e
mp
has
is on
c
an
bin
ati
on
s li
%c
kj t
o s
how
ti
egra
ded
pe
rfo
mri
ce
(i
.e.,
hi6
:ier
s
pe
ds
, sh
ort
er
<is
ibil
ity
ra
ng
es,
an
d s
ho
rte
r d
eli
ne
ati
on
cle
ae
ntz
).
Tjr
yi?
al examples o
f v
5ii
bil
i;:
and
c
mfi
gu
rati
on
ccm
dit
ion
s a
re i
lks-
tmt,
?d
i? P
iis
. +;
and 7.
Ir, Pi&. 0
it
is
a
rpa
ren
t h
a,
red
u-e
d visual r
nw
e a
ffe
cts
l
~t
rr
ll
p
osit
ion
, h
ead
%,-
s. an
d
I-u
r'n
ture
cu
es
. In
Fig.
'/ th
e r
ffc
cts
for
each
co
nd
itio
n a
cco
rdin
g t
o t
he
fo
llo
win
g p
roce
du
re.
The
ex
per
imen
ter
wou
la
init
ial&
s
et
the
vis
ibil
ity
ran
ge,
th
en a
sk t
he
su
bje
ct
to p
osi
tio
n
a li
ne
, w
hic
h a
pp
eare
d a
cro
ss t
he
roa
dway
, to
th
e p
oin
t a
t w
hich
th
e d
elin
ea-
tian
dis
app
eare
d.
The
lin
e p
osi
t;o
n
was
c
on
tra
lle
d w
ith
a t
en-t
.-n
po
ten
-
tio
me
ter a?&
was
re
turn
ed
to
ze
ro b
etw
een
esti
mat
es.
The
ex
per
imen
ter
wou
ld
rep
eat
this
pro
ced
ure
se
ve
ral
tim
es,
rea
dju
stin
g t
he
vis
ibil
ity
ran
ge
betw
een
est
ima
tes
in a
n
ite
rati
ve
pro
ced
ure
un
til
the
de
sire
d v
isib
ilit
y r
ang
e,
as
incL
icat
ed b
y th
e
sub
jec
t, w
as
ach
iev
ed.
Des
crib
ing
fu
nct
ion
an
d p
erfo
rman
ce m
easu
rem
ents
w
ere
ob
tain
ed s
unde
r tw
o
task
co
nd
itio
ns
for
each
ex
per
imen
tal
con
dit
ion
. O
ne
task
req
uir
ed
reg
ula
tin
g
ag
ain
st a
ran
dom
win
d g
ust
-lik
e
dis
turb
ance
ad
ded
in
at
the
ste
eri
ng
sig
na
l
inp
ut
to t
he
veh
icle
eq
uat
ion
s o
f w
tio
n a
s il
lus
tra
ted
in
Fig
. 2.
T
his
ta
sk
req
uir
e6
co
mp
ensa
tory
co
ntr
ol
beh
evio
r a
s t
he
roa
rbra
y w
as
stra
igh
t an
d t
he
dis
turb
ance
co
uld
no
t be
o
bse
rved
oth
er
than
in
its
eff
ec
t on
ve
hic
le m
oti
on
s.
A
seco
nd
ta
sk i
nv
olv
ed f
oll
ow
ing
a w
ind
ing
ro
ad w
hich
all
ow
ed f
or
pu
rsu
it c
on-
c.
m
tro
l b
ehav
ior
if t
he
viz
ua
l sc
ene
pro
vid
ed f
or
adeq
uat
e cu
rvat
ure
per
cep
tio
n.
m
Cm
tu
re
c-n
ds
for
this
ta
sk w
ere
add
ed i
nto
th
e e
qu
atio
ns
as
sh
orn
in
Mg.
2 in
ad
dit
ion
to
cu
rvin
g t
he
dis
pla
yed
roa
dway
.
The
rre
thod
fo
r o
bta
inin
g d
riv
er
des
crib
ing
fu
nct
ion
da
ta i
s s
how
n in
Kg.
9.
A
Fo
uri
er a
na
wz
er
(Ref
. 19
) g
ener
ated
a su
n o
f si
ne
wav
es
inp
ut
(Tab
le
3)
tha
t w
as
inje
cte
d i
nto
th
e s
yst
em a
s e
ith
er
a co
mm
and
or
a d
istu
r-
ban
ce,
and
rec
eiv
ed b
ack
ano
ther
sy
stem
qu
an
tity
whi
ch w
as
sub
seq
uen
tly
Mu
rie
r
on
sly
zed
at
each
of
the
i
np
t f
req
~e
nc
ies
cry.
As
no
ted
in
Fig
. 8 t
he
ac
tua
l q
ua
nti
tie
s u
sed
to c
ompu
te t
he
eq
uiv
alen
t
dri
vc
r/v
eh
icle
o
pen
-lao
p
des
crib
ing
m
nc
tio
n d
epen
d on
t.h
e ta
sk i
np
ut.
o
r th
e w
ind
ing
ra
ad
cam
and
iz
pu
t ca
se,
whe
re p
urs
uit
beh
avio
r is
po
ssib
le,
the
em
r (
re)
to i
np
ut (rc) d
escr
ib-n
g
fun
ctio
n
is
com
pute
d an
d t
hen
tra
nsf
orm
ed
to g
ive
an
equ
ival
ent.
op
en-l
oo
p
tra
nsf
er
fhn
ctio
n r
/re
. F
or t
he
co
mp
ensa
toy
,
win
d ~
~u
zt
d
istu
rban
ce
in
pt
th
e e
qu
ival
ent
op
en-l
oo
p
tra
nsf
er
fun
ctio
n
is
foun
d :'ran
op
erat
ion
s on
tn
e 6
,/tid
ra
tio
, a
s d
escr
ibed
in
Ref
. 9.
, D
rive
r S
teer
ing
Act
ion
,
5
Ano
ly z
er
a 1
Win
d G
ust
Dis
turb
once
Inp
ut
Dyn
amic
s
h D
ispl
ayed
Sp
eed-
- C
urva
ture
S
I/c
= x
~~
si
n(
w~
t+
+~
) Fo
uri
er
6.1
Ana
lyze
r
6 /
Win
ding
Roo
d C
omm
and
/muf
Fig
ure
8.
D
riv
er D
escr
ibin
g h
ct
io
n M
easu
rem
ent
Tec
hn
iqu
e
TABL
E 3.
IRPVP
AM
PLIT
UD
ES m
Im
QU
mcI
ES
Aft
er
the
a-s
cri
bin
g
ibn
ctio
n d
ata
are
dev
elo
ped
, an
op
tim
al i
de
nti
fi-
ca
tio
n r
ou
tin
e i
s u
sed
to
fin
d d
riv
er
par
amet
ers
for
the
Fig
. 2
syst
em m
odel
tha
t w
ill
giv
e a good m
atch
to
th
e m
easu
red
de
scri
bin
g f
un
ctio
n d
ata
. - m
\O
A
s an
exa
mpl
e co
nsi
der
th
e d
ata
ill
us
tra
ted
in
Fig
. g
for
the
tw
o b
ase-
li
ne
vis
ibil
ity
co
nd
itio
ns.
T
he m
easu
red
de
scri
bin
g f
un
ctio
ns
wer
e av
erag
ed
ac
ross
s-h
su
bje
cts
, an
d t
he
de
scri
bin
g f
un
ctio
n f
its
mat
ch t
he
da
ta r
ath
er
wel
l.
The
ch
an
ctc
ris
tic
eff
ec
t o
f th
e c
urv
e p
erce
pti
on
par
amet
er K*
is
app
aren
t in
bo
th c
ase
s in
com
pari
ng t
he
cu
apen
sato
ry
(win
d g
ust
dis
turb
an
ce
)
and
~m
rsu
it, (
win
din
g r
oad
com
aand
) ta
sks.
WIND
G-&
'I A
MPL
Il'mES
(WU
IV
AL
~~
ER
OKE
W
HEE
L A
EU
, d
eg)
Mod
el p
aram
eter
s fo
r b
oth
st
ee
rin
g t
ask
s o
ver
a
num
ber
of
vis
ibil
ity
and
de
lin
ea
tio
n c
on
fig
um
tio
n c
on
cttt
ion
s a
re c
ou
pre
d i
n T
able
1;.
The
mos
t
am
re
nt
co
nsi
ste
nt
eff
ec
t in
th
e c
om
ple
te m
odel
par
amet
ers
seem
s to
be
the
red
uct
ion
in
cu
rvat
ure
per
cep
tio
n (KR~) wit
h i
ncr
ease
d c
on
fig
ura
tio
n
vis
i-
bil
ity
pa
me
ter
Cv.
T
his
re
lati
on
ship
is p
lott
ed
in
Fig
. 10.
Alt
ho
ug
h t
he
eff
ec
ts a
re n
ot
as
ne
at
as
we
mig
ht
ho
pe,
th
e t
end
enci
es a
n q
uit
e c
lea
r:
c~~
p
erc2
pti
on
ga
in d
ecre
ases
wit
h i
ncr
easi
ng
co
nfi
gu
rati
on
vis
ibil
ity
par
amet
er,
and
dec
reas
ing
sp
eed
. C
hang
es d
ue
to
Cv
are
un
do
ub
ted
ly a
sso
cia
ted
wit
h t
he
am
ount
of
curv
atu
re i
nfo
rmat
ion
pro
vid
ed b
y th
e v
isu
al
sep
ien
t o
n a
ROA
D C
'URV
Al"J
RE AMP'.ITUDES
(IN
VE
RSE
RA
DIV
S OF
CV
RV
ATI
XZ,
ft-'
)
1%
(=dl sec ) - 1.462
1.297
2.167
1.147
2.060
1-57
2.21
0.76
1.302
2.w
0-5b 0.762
0.6b3
1.117
1.347
1.2JI3
0.681 1.355 -
m/ CYCLE mGTH
(ft) - 15/40
15/40
1 S/LO
2/40 2/40
SP5 9/25 9/23
15/40
15/40
15/40
2/40
?!LO
2/40
2/40 2/40
2/40
19/40 15/40
CONF'rn- SATION rE nILITY PARAMETER,
Cv
delineat ion (roe Table 1).
al
Hea
ding
Gai
n
6) E
quiv
alen
t D
ynam
ic L
wk
-Ah
ead
Dis
lonc
e
C/ E
qu
ival
ent
Sys
tem
Lot
cncy
Figure
12.
Ilri
ve
r/~
eh
icle
Sys
tem
me
nd
ed
Cro
sso
ver
Me
1
Par
smet
ers
for
Cau
pm
sato
ry T
ask
the
ve
hic
le lag
inc
rea
ses
wit
h s
pee
d w
her
eas
the
eff
ec
tiv
e t
ine
delay
dec
reas
es w
ith
sp
eed
, s
o th
is
"erp
lan
stfo
nw
ia
in t
he unmg &
tree
tio
n.
The
sam
pli
ng
in
terv
al
of
the
das
hed
lin
es
Fs
giv
en bg
whe
re x,
ir t
he
de
lin
ea
tio
n c
ycl
v l
eng
th.
Cba
Fgc
in z
e is p
rap
ort
bb
d to
sam
pli
ng
in
terv
al
(Ref
. 15
),
so t
he
win
tio
n o
f re
wit
h b
oth
.peed a
nd
Cv
is i
n t
he
rig
ht
dir
ec
tim
. A
cco
rdin
gly
, w
e a
ttri
bu
k t
& z
e -s
pi-
marily
to s
amp
lin
g p
roce
sses
a
sso
cia
ted
wit
h t
he
de
lin
ea
tio
n W
he
d l
ine
s
and
sp
eed
.
The
sam
pli
ng
pro
cess
whi
ch a
ffe
cta
th
e M
ve
r's
t
he
del
ay S
kX
dd
'A
0
hav
e so
me
infl
uen
ce o
n th
e n
ois
e o
r st
oc
ha
stic
cQ
lpo
nm
t O
f hi.
8-
ac
tio
ns.
In
Fig
. 13
we
sb
w th
e p
rop
ort
ion
of
mis
e o
r re
maa
nt t
hat i.
un
co
rre
late
d w
ith
th
e d
riv
er'
s a
cti
on
s in
co
un
tera
ctin
g r
iad g
ust
s o
r S
ktr
-
ing
alo
ng
a w
ind
ing
road
. There
is a
te
nd
ency
for M
ve
r n
ois
e to
in-lr
e
bo
th v
ith
co
nfi
g!y
etio
n p
utm
ete
r nn
d sp
eed
.
The
in
trm
ltte
nc
y o
f a
eli
ne
ati
on
ap
pn
ren
tly
aff
ec
ts d
river
rwm
bn
t;
how
ever
, th
i3 e
ffe
ct
is i
ncr
ease
d a
t h
igh
er 8
peed
a (i
.e.,
hi
gtu?
r delirwa-
tio
n s
ampl
e ra
tes
) in
co
ntr
ast
to
th
e
th
e d
elay p
na
lty
(Pi&
12
) w
hic
h
dec
reas
ed v
ith
in
cn
aa
ing
speed.
Lhe
se t
wo
co
ntr
a~
tin
g eff
ce
t. on d
river
beh
avio
r ex
pla
in t
he
re
lati
ve
ly c
on
sist
an
t e
ffe
ct
of
sp
ed
on
perf
o-ce
u
nd
er a
dv
erse
v
isib
ilit
y s
how
n in
Fig
. 14
. A
t lo
w speeds, t
h s
lar inter-
mit
ten
cy o
f d
eli
ne
ati
on
cau
ses
app
reci
able
in
cre
ase
s in
dri
rcr
tim
e d
ela
y
whi
ch d
egra
des
per
form
snce
; w
hil
e a
t h
igh
speeds, d
riv
er
no
ise
in
cle
ase
s,
whi
ch a
gai
n d
egra
des
per
form
ance
. A
lso
no
te t
ha
t fo
r the curve-following
data d
riv
er
no
ise
incr
ease
s ap
pre
ciab
ly u
nd
er th s
smc
co
nd
itim
s tb
at
led
t:,
red
uce
d c
urv
atu
re p
erce
pti
on
(F
ig.
10).
F
urt
kra
~re
, the
cm
-f
ol
la
fn
g
data
show
a p
rop
ort
iom
tely
gre
ate
r c
on
fig
ura
tio
n v
isib
ilit
y p
a-te
r sm
- s
itiv
ity
, c
on
sist
en
t w
ith
th
e F
ig.
14 p
erf-
nee
data.
A fin
d c
bs
vra
tio
a
is t
ha
t tn
. so
lid
ed
ge
lin
e r
edu
ces
dri
ve
r n
ois
e o
ver
tb
e d
ashe
d o
r no
rigbt
lane
lin
e c
ases
, w
hich
(a
s w
ith
pre
vio
usl
y d
iscu
ssed
data) i
s c
on
sist
en
t vlth
a lo
wer
eq
uiv
ale
nt
Cv.
1 u from ANOV
Figure 15. Driver Remnant as a mnction of Spced and Configuration Visibility Parameter
0 20 40 50 80 Speed, U,(fllsec)
b l Pursuit control Ipotn lol~owinp o/ong o wtnding mud)
Lone Dispersion, cry (11) - - N
Probability o) Lam Eseedoms (Percent 1
Lone Dispersion, cry (ft) - - N
b o in b I I I I
Probab~lity of Lono Eacwdonce I Percent 1
Adv
erse
v
isib
ilit
y r
es
tric
ts t
he
dri
ve
r's
per
cep
tio
n o
f au
tom
ob
ile
pt
h
and
mo
tio
n i
nfo
rmat
ion
re
qu
ire
d f
or
ste
eri
ng
co
ntr
ol.
T
hes
e p
erc
ep
tua
l
rest
ric
tio
ns
can
be
qu
an
tifi
ed
in
te
rns
of
the
dri
ve
r's
dy
nan
ic s
tee
rin
g
beh
avio
r in
res
po
nse
t.
ran
dan
dis
turb
ance
s an
d p
ath
csa
a~an
ds.
C
om
bin
atio
ns
of
red
uce
d v
isib
ilit
y a
n2
ie
lin
en
tio
n c
on
fig
ura
tio
n
(i.e
.,
inte
rmit
ten
t d
ash
ed
or
do
tte
d l
ine
s)
ten
d t
o i
-. $
we
in
crea
sed
tra
ns
prt
del
ay i
n t
he
dri
ve
r an
d
imp
Rir
his
per
cep
tio
n o
f ro
ad c
urv
atu
re.
Red
uced
vis
ibil
ity
als
o i
nd
uce
s a
red
uct
ion
in
eq
~iv
ale
nt d
ynam
ic l
oo
k-a
hea
d
dis
tan
ce
(th
e i
nv
erse
of
late
ral
po
siti
on
err
or
ga
in)
bu
t d
oes
no
t ap
pea
r to
in
flu
ence
th
e w
eig
hti
ng
or
gai
n
the
dri
ve
r a
pp
lie
s to
hea
din
g e
rro
rs.
The a
bo
ve
eff
ec
ts a
pp
ear
to b
e re
late
d t
o t
he
ap
par
ent
inte
mlt
ten
t o
r
san
ple
d n
atu
re o
f d
eli
ne
ati
on
un
der
red
lrce
d v
kib
ilit
y c
on
dit
ion
s.
Dri
ver
tim
e cl
elay
, re
, in
crea
ses
at
slo
wer
sp
eed
s,
due
to
dec
reas
ed s
amp
lin
g f
re-
qu
ency
, ev
en t
ho
@
veh
icle
dyn
amic
la
gs
dec
reas
e w
ith
sp
eed
. T
his
eff
ec
t
ind
uce
d a
so
mew
hat
ca
ep
ell
ing
urg
e in
som
e su
bje
cts
to
sp
eed
up
in o
rder
to
inc
rea
se t
he
ir i
nfo
rmat
ion
ra
te,
wh
ich
is a
ra
the
r in
sid
iou
s ph
enom
enon
if
Y
) u
tr
ue
fo
r re
al-w
orl
d
dri
vin
g,
sin
ce
it
mi&
t en
cou
rag
e dri
vers
to m
ain
tain
spee
ds
wit
h a
sso
cia
ted
sto
pp
ing
dis
tan
ce
s ex
ceed
ing
th
eir
vis
ua
l ra
ng
e.
Cha
nges
in
cu
rve
per
cep
tio
n g
ain
als
o a
pp
ear
to
be
rela
ted
to i
nfo
rma-
tio
n s
amp
lin
g,
wit
h K
~.c
dec
reas
ing
wit
t d
ecre
ased
sp
eed
an
d/o
r re
du
ctio
n
in the a
mou
nt o
f p
erc
ep
tua
l in
form
atio
n
(i.e
.,
incr
ease
d C
v).
In t
his
cas
e
curv
atu
re p
erce
pti
on
is
en
han
ced
wit
h s
pee
d,
whi
ch may
als
o b
e re
late
d t
o
"str
eam
er"
the
ori
es
of
drt
ve
r p
erce
pti
on
whe
re
the
curv
ed p
ath
nat
ion
o
f th
e
ca
r i
s i
nd
ica
ted
by
the
cu
rved
mo
tio
n o
f v
isu
al
fie
ld e
lem
ents
.
Th
is r
ese
arr
h h
ai
glv
en s
me
in
sig
ht
into
dyn
amic
s o
f d
riv
er
per
cep
tio
n,
and
th
e r
ole
pla
yed
by
road
mar
kin
gs
use
d t
o d
eli
ne
ate
th
e c
-nde
d pathway.
The
tec
hn
iqu
es d
evel
op
ed h
ere
shcu
ld b
e .
11 fo
r fu
rth
er
rese
arc
h i
n t
his
are
a a
nd
alloy v
ario
us
qu
esti
on
s t
o b
e a
n
:red
ab
ou
t th
e r
eq
~ir
ed
or
op
tW
-on
fig
ura
tio
ns
of
ro
a~
sy
d
eli
ne
ati
on
.
1.
Seg
el.
L.,
'?h
eo
reti
ca
l P
red
icti
on
an
d E
qe
~4
ne
nta
l Su
bst
an
tia
tio
n o
f th
e ~
es
po
ke
of
the
Au
tom
ob
ile
to s
tee
rin
g C
~n
tr
ol
,~
in R
esea
rch
in
Au
tam
bil
e S
tab
ilit
y a
nd
Co
ntr
ol
and
ir.
Ty
re P
erfo
rman
ce,
bn
dm
, Insti-
tute
ofM
ech
anic
8l
En
gin
eers
, 19
57.
2.
All
en,
R.
X.,
an
d D
. T
. k
Ru
er,
'T
he
Eff
ec
t o
f A
dv
erse
Vis
ibil
ity
on
D
riv
er S
tee
rin
g F
'erf
orm
ance
in
an
Au
km
ob
ile
Sim
ula
tor,
" p
rese
nte
d a
t th
e 1
977
SAE
Inte
rna
tio
na
l A
utom
obil
e E
ng
inee
rin
g C
on
gre
ss a
nd
Fa
ps
i-
tio
n,
De
tro
it, 28
'8b
.A
Mar
. lw
.
3.
Gib
son
, J.
J.,
"Uhat
G
ives
Ris
e to t
he
Per
cep
tio
n
of
Mti
on
," P
sych
. R
evie
w,
Vol
. E, 19
69,
pp
. 33
5-34
6.
-
4.
Gor
don,
D
. A
., "P
erce
ptu
al B
asis
of
Veh
icu
lar
Gu
idan
ce,"
P
~b
lic
Rad
s,
VO
L
34
, no
. 3,
A%
. i%
6,
pp
. 53
-68.
5.
Pal
mer
, E
. A.
, "E
xp
erim
enta
l D
eter
min
atio
n
of
Huc
an A
bil
ity
to
Per
ceiv
e A
irc
raft
Aim
poin
t f .om
Exp
andi
ng G
rad
ien
t C
ues,
" A
ero
spac
e M
edic
al
Mee
ti?:
San
Fra
nci
sco
, P
rep
rin
t o
f S
cie
nti
fic
Pro
epsm
, My 1
969,
PP.
17
In
.
6.
Calvert, E.
S.,
V
isu
al
Ju-n
ts
in h
bti
on
," J.
Inst
. N
avig
atio
n,
Vol
. 7
, 19
57.
7.
Hai
nes
, R.
F
., "A
R
evie
w o
f P
eri
ph
era
l V
isio
n C
ap
ab
ilit
ies
for
Msp
.?ay
W
yo
ut
Des
ign
ers,
" F
'roc.
S
.I.D
., V
o1. 16/4,
Mh
Qyarter,
lZ5
, pp
. 3
8-2
49
.
8.
McF
mer
, D
. T
., R.
W
. W
en
, D
. H.
W
eir,
an
d R.
H. Klein,
"Aew
Res
ult
s in
Dri
ver
Ste
eri
ng
Co
ntr
ol
Ho
del
s,"
Him
ran
Fac
tors
, d
pe
cia
l Is
suc,
fo
rth
com
ing
.
9.
McR
uer,
D.
T.,
D. H.
Wei
r,
H.
R. Je
x,
R.
E.
hb
gd
alen
o, and R
. W
. K
Ue-
, "h
ka;u
rem
ent
of
~r
ive
r/~
eh
icle
W
fiti
loo
p I
iesp
onse
P
rop
ert
ies
wit
h a
S
ing
le D
istu
rban
ce I
np
ut ,"
IEE
E T
ran
s.,
Vol
. SM
C-5
, R
o.
5,
Sep
t.
1975
, PP.
490-
497.
10.
McL
ean,
J.
R.,
and
E.
R.
tio
ffb
arin
, T
he
Eff
ec
ts o
f R
est
ric
ted
Prcvicv
on
Dri
ver
Ste
eri
ng
Co
ntr
ol and
Per
form
anc?
,"
Hm
m
Fac
tors
, V
ol.
15,
No.
4,
Aug
. 19
73, pp.
42
1Ji
30
.
11.
Wei
r,
D.
H.,
and
D.
T.
McR
uer,
"Dyn
amic
s o
f D
riv
er/V
ehic
le
Ste
eri
ng
C
on
tro
l,"
Au
tom
atic
s,
Vol
. 6,
no
. 1
, Ja
r..
197'
3,
pp.
87-9
8.
12.
McR
uer,
I).
T.,
R.
H.
Kle
in,
et
al.
, A
uto
mo
bil
e C
on
tro
lla
bil
ity
-
Dri
ver
/Veh
icle
R
espo
nse
for
Ste
eri
ng
Co
ntr
ol.
V
ol.
I:
S- R
eport.
Vol
. T
I:
Su
pp
ort
ing
IS
rper
imen
tal
Res
ult
s,
DO
T H
S-B
Ol 4C7
end
IE
5-80
1 b5, F
eb.
197'
5.
13.
&h
er
, D.
T..
"Sim
pli
fied
A
uta
mo
bil
e S
tee
rin
g D
ynam
ics
for
Dri
ve
r C
on
tro
l,"
pre
sen
ted
to
th
e S
AE A
ero
spac
e C
on
tro
l an&
Gui
dnnc
e d
yste
m8
!:m
. Mtg.
No.
35
, P
alo
Alto, C
ali
f.,
19
-21
#rr
. 19
75.
1L.
HcR
uer,
f.
T.,
an
d E.
3.
Kre
nd
el,
Ma
the
mti
ca
l k
&l
s
of Huasn
Pil
ot
Behavior, A
CA
RD
-AG
-1P
B.
:an.
1n
i.
1"
All
en,
R. W.,
W.
F.
Cle
men
t,
and
H.
R.
Jex
, R
esea
rch
OP
Cis
pls
y S
cann
i- S
ax
pli
ra,
and
Rec
on
stru
ctio
n Using
Se
pa
rate
Win
an
d S
eco
nd
ary
Tra
cki-
T
a.;k
s, H
ASA
CR
-156
9, July
1970
.
15
. A
lle
n. R,
W.,
J.
R.
Hog
ge,
ord
S.
if. Schwartz,
"A
Sim
htc
r f
or
Res
earc
h
in D
riv
er,
V
ehic
le a
nd
Env
iron
men
t In
tera
cti
on
,"
pre
sen
ted
at
th
e 5
6th
M
eeti
ng
of
the
TRB,
Jan
. 19
77.
17,
Tra
ffic
M
anua
l,
Sta
te o
f C
ali
forn
ia,
bs
ine
ss
an
d T
ran
spo
rta
tio
n Q
ency
, D
ept.
o
f h
blc
c W
orks
, 1
91
.
18.
Fb
nu
al
on U
nif
on
n T
raff
ic C
on
tro
l D
evic
es
for
Str
ee
ts a
nd H
igh
U4
~,
Ad
er
d H
ighw
ay A
Mn
.,
19
1.
19.
All
en
, R
. W
., nn
d H.
R
. Je
x,
"A
Slm
ple
Fo
uri
er
An
nly
sis
Tec
hn
iqu
e fo
r .%
asur
lng
the
Dyn
amic
R
e-po
nse
of
lBnu
Fbl
Car
t13
1 S
y~
ten
IS,"
bans.,
Val
. S
X-2
, N
o. 2, N
o. 19
72,
pp
. 6-
3.
. M
cRue
r,
D.,
D. Crahsn,
E.
Km
nd
el,
and
Y.
Re
ise
ne
r, Jr.
, H
ua
n P
ilo
t C
.a
-3m
ics
in C
orep
ensa
toxy
Sy
scea
s -Theory.
HD
dels
, an
d E
~~
er
iPm
ts
with
m
%
roll
ed
E
lem
ent
and
Wrc
ing
Fu
nct
ion
V
ari
ab
les,
A
FR
>GT
R-7
5-15
, July
1%5-
Th
is work was
sup
po
rted
by the
Fe
de
ral Highway A
dm
inis
trat
ion
u
nd
er
Con
- tr
ac
t D
UI'
-nl-
l1-8
8.%
. D
r. Donald A
. O
ordo
n o
f th
e T
raff
ic S
ys
tas
Div
isio
n
serv
ed
as
th
e C
on
tra
ct
Te
ch
nic
al
Wn
ager
.
