<s>
A	O
diagrammatic	B-Application
sign	I-Application
or	O
diagrammatic	B-Application
guide	I-Application
sign	I-Application
is	O
a	O
type	O
of	O
guide	O
sign	O
that	O
indicates	O
destinations	O
using	O
a	O
large	O
,	O
map-like	O
illustration	O
of	O
the	O
road	O
layout	O
.	O
</s>
<s>
The	O
term	O
is	O
most	O
commonly	O
associated	O
with	O
diagrammatic	B-Application
signs	I-Application
installed	O
ahead	O
of	O
forks	O
in	O
controlled-access	O
highways	O
to	O
indicate	O
the	O
destination	O
of	O
each	O
lane	O
.	O
</s>
<s>
Diagrammatic	B-Application
signs	I-Application
are	O
specified	O
in	O
the	O
Manual	O
on	O
Uniform	O
Traffic	O
Control	O
Devices	O
developed	O
by	O
the	O
United	O
States	O
Federal	O
Highway	O
Administration	O
,	O
as	O
one	O
of	O
several	O
options	O
for	O
exits	O
and	O
splits	O
on	O
multilane	O
freeways	O
.	O
</s>
<s>
A	O
simpler	O
kind	O
of	O
diagrammatic	B-Application
sign	I-Application
without	O
lane	O
detail	O
is	O
allowed	O
for	O
indicating	O
a	O
series	O
of	O
exits	O
along	O
a	O
conventional	O
street	O
or	O
roundabout	B-Application
.	O
</s>
<s>
Diagrammatic	B-Application
signs	I-Application
have	O
been	O
a	O
recommended	O
method	O
of	O
signposting	O
exits	O
and	O
splits	O
in	O
Massachusetts	O
and	O
New	O
York	O
.	O
</s>
<s>
On	O
December	O
14	O
,	O
2020	O
,	O
the	O
Federal	O
Highway	O
Administration	O
proposed	O
several	O
changes	O
to	O
an	O
upcoming	O
edition	O
of	O
the	O
MUTCD	O
that	O
would	O
streamline	O
some	O
diagrammatic	B-Application
signs	I-Application
or	O
eliminate	O
the	O
use	O
of	O
diagrammatic	B-Application
signs	I-Application
on	O
freeways	O
and	O
expressways	O
,	O
citing	O
the	O
successful	O
introduction	O
of	O
arrow-per-lane	O
signs	O
.	O
</s>
<s>
Simplified	O
diagrammatic	B-Application
signs	I-Application
would	O
continue	O
to	O
be	O
used	O
at	O
roundabouts	B-Application
and	O
other	O
conventional	O
streets	O
where	O
lane	O
detail	O
is	O
not	O
required	O
.	O
</s>
<s>
Diagrammatic	B-Application
signs	I-Application
have	O
been	O
shown	O
to	O
be	O
less	O
effective	O
than	O
conventional	O
,	O
text-only	O
signs	O
(	O
e.g.	O
,	O
""	O
)	O
and	O
overhead	O
arrow-per-lane	O
signs	O
because	O
of	O
the	O
additional	O
time	O
it	O
takes	O
to	O
comprehend	O
them	O
.	O
</s>
<s>
A	O
2006	O
study	O
by	O
the	O
Texas	O
A&M	O
Transportation	O
Institute	O
found	O
that	O
diagrammatic	B-Application
signs	I-Application
performed	O
poorly	O
compared	O
to	O
text-only	O
signs	O
for	O
left-side	O
exits	O
and	O
performed	O
similarly	O
to	O
text-only	O
signs	O
for	O
right-side	O
exits	O
.	O
</s>
<s>
A	O
2008	O
study	O
found	O
a	O
clear	O
advantage	O
to	O
arrow-per-lane	O
signs	O
compared	O
to	O
diagrammatic	B-Application
signs	I-Application
,	O
especially	O
among	O
older	O
drivers	O
.	O
</s>
