Series
GEO-131-
Series or
GEO-130p
su
be
tw
M
in
ee
im
n
um
cu
er
rv
di
el
es
st
ev
an
to
at
ce
ac
io
co
n
m
tr
m
an
od
si
at
ti
e
o
n
1145 ft (350m)
1145 ft (350m)
Trumpet A Alternate
Dimensions typical to
)
5m
Series
GEO-101-
Series or
(15
50
page 2
r
jo
Ma
GEO-100-
)
m
24 ft (7.2m)
ft
55
0
(1
16 ft (4.8m)
0
5
0 f
t
those of Trumpet B on
16 ft
M
ov
(4.8m)
e
m
e
nt
s
1145 ft (350m)
GEO-110-Series
GEO-100-Series,
GEO-101-Series or
16 ft (4.8m)
One lane to
ft
1145
)
(350m
each direction
G
E
S
O
e
ie
E
O
S
s
-1
e
0
-
r
1
e
3
o
3
ri
s
16 ft
-1
r
G
-
(4.8m)
G
3
-1
s
1
s
0
-
r
0
e
0
o
-
Series
GEO-131-
Series or
GEO-130-
e
ri
)
m
= Amounts for double lane design
ie
O
S
-1
r
E
ft
XXX
O
e
G
5
95
(1
= Clear vision areas
E
S
6
LEGEND
One lane from
each direction
TRUMPET A
NOT TO SCALE
GEOMETRIC DESIGN GUIDE FOR
Michigan Department of Transportation
BY:
TRUMPET TYPE
ENGINEER OF DELIVERY
TRAFFIC AND SAFETY
INTERCHANGE
DRAWN BY:
DJF
CHECKED BY:
IRG/JAT
BY:
09/06/2007
ENGINEER OF DEVELOPMENT
FILE: PW/RD/TS/Geom D/mdot GEO350B EOC.dgn
REV.
09/06/2007
PLAN DATE:
SHEET
GEO-350-B
1
1 OF 3
each direction
Series
GEO-101-
Series or
-
0
r
3
O
)
5
3
5m
s
-
1
ie
E
3
r
G
e
-1
O
S
(1
9
6
o
-1
ft
GEO-100-
One lane to
s
e
E
ri
G
e
S
16 ft
(4.8m)
-
0
3
-1
O
E
G
r
o
s
-
ie
1
3
r
-1
e
S
s
O
E
G
e
ri
e
S
60 ft (18m)
Minimum E to E
One lane from
each direction
1145 ft (350m)
ve
me
nt
s
Series
GEO-131-
GEO-130-
Series or
Series
16 ft (4.8m)
Maj
or
Mo
(80m
260
ft M
ax
24 ft (7.2m)
)
16 ft (4.8m)
GEO-131-
GEO-130-
(4.8m)
Series or
16 ft
1145 ft (350m)
LEGEND
GEO-110-Series
GEO-100-Series,
(350m)
GEO-101-Series or
e
at
ce
od
an
m
st
m
on
di
ti
co
si
ac
um
an
im s to
tr
in
e
M
rv
on
ti
cu
n
va
le
ee
re
tw
pe
su
be
1145 ft
= Clear vision areas
XXX
= Amounts for single lane design
TRUMPET B
NOT TO SCALE
MICHIGAN DEPARTMENT OF TRANSPORTATION
TRAFFIC AND SAFETY GEOMETRIC DESIGN GUIDE
FILE: PW/RD/TS/Geom D/mdot GEO350B EOC.dgn
REV.
09/06/2007
09/06/2007
PLAN DATE:
SHEET
GEO-350-B
2 OF
3
NOTES:
1) For ramps longer than 2000 ft (610m) consider two lanes to allow for passing
opportunities.
2) Spiral transitions should be used on new ramp alignments based on the design
speed of the curve and the radius as shown in the table of the Road Standard Plan
R-107-Series.
The table gives the maximum radius in which a spiral should be used.
3) See geometric design guide GEO-300-Series for clear vision area requirements.
4) These design concepts are for new construction. Where modifications may be
needed for retrofitting to existing road features, consult the Geometric Design
Unit of Lansing Traffic and Safety.
NOT TO SCALE
MICHIGAN DEPARTMENT OF TRANSPORTATION
TRAFFIC AND SAFETY GEOMETRIC DESIGN GUIDE
FILE: PW/RD/TS/Geom D/mdot GEO350B EOC.dgn
REV.
09/06/2007
09/06/2007
PLAN DATE:
SHEET
GEO-350-B
3 OF
3