HomeMy WebLinkAboutCD-203 Left Turn Transition
A.... .
. ....
TAPER FOR MEDIAN SPEED-CHANGE LANES
....
.... CD EDGE OF PAVEMENT TRAFFIC STRIPE Ot
CURB
.................... .
...................... .
WIDTH OF SPEED-
CHANGE LANE
E Q) .....
.....
c
AD = LENGTH OF TAPER.
AB = BC = CD = 1/3 AD
AB' & C' 0' ARE PARABOLIC CURVES
~ DATA FOR POINT B'
L:::::I DATA FOR POINT C'
LENGTH OF
TAPER-FEET
60 90
Distance from Point
OFFSET DISTANCE
00'=10' 00'=11' 00'=12'
B
0 0 0
5 7.5 0.16 0.17 0.19
10 15 0.62 0.69 0.75
15 22.5 1.41 1.55 1.69
20 30 2.50 .75 3.0 B'
30 45 60 5.00 5.50 6.00
. . . . . . . . . ...... . ..... .... ............ .............. ...
.....-:-:-::40 .... :.:.:.:.:.:.60:.:.:.:.:-::.:.::.:.:.80-:':' -:-:7.50 :::::-:-::8.25 -:-:-::-:-::-:-9.0Q. .. C'
....
45 67.5 90 8.59 9.45 10.31
50 75 100 9.38 10.31 11.25
55 82.5 110 9.84 10.83 11.81
60 90 120 10.00 11.00 12.00
C
NOTES:
<D THE TABLE GIVES OFFSETS FROM A BASE LINE PARALLEL TO THE EDGE OF PAVEMENT AT
INTERVALS MEASURED FROM POINT A. ADD E FOR MEASUREMENTS FROM EDGE OF
PAVEMENT.
(2) WHERE EDGE OF PAVEMENT IS A CURVE, NEITHER BASE LINE NOR TAPER BETWEEN B & C
WILL BE A TANGENT. USE PROPORTIONAL OFFSETS FROM B TO C.
Q) THE ADOPTED OFFSET E IS USUALLY 2' ALONG OUTSIDE EDGE OF PAVEMENT BUT MAY
VARY IN SOME CASES.
LEFT TURN TRANSITION
SCALE: NOT TO SCALE
DATE: SEPTEMBER 13, 2006
DRAWN BY: LDH
V:\CAD\NEW STANDARDS
APPROVED: . ~
~L~~
PUBLI WORKS DIRECTOR CD-203