§ 155.045 LOCAL RESIDENTIAL SUBDIVISION ROADS.

   (A)   Cul-de-sacs;

   (B)   Dead end roads: less than 2,500 feet in length;

   (C)   Short connecting roads: one block long or that extend on a block by block basis;

   (D)   Loop roads: less than one mile in length; and

   (E)   Other roads that do not connect thoroughfares or serve major traffic generators. These roads do not have "collector" characteristics.

Terrain Classification	Level (Cross Slope Range of 0% to 8%)	Rolling (Cross Slope Range of 8.1% to 15%)	Hilly (Cross Slope over 15%)
Right-of-Way Width
Curb and gutter section	40'	40'	40'
Shoulder section	45'	45'	45'
Pavement Width
Curb and gutter section	*26' G-G	*26' G-G	*26' G-G
Shoulder section	18'	18'	18'
G-G refers to face to face of standard curb and gutter section, bottom of the "V" to the bottom of the "V" for the valley types section. Other types will be reviewed by the District Engineer with the GG limits applicable
Minimum Shoulder Width
Shoulder section, shoulder width between 4' to 6' shall be approved by the District Engineer considering adjacent land characteristics	6'	4' to 6'	4' to 6'
Maximum Cut and Fill Slopes	2:1	2:1	1-1/2:1
Design Speed	30 mph	25 mph	20 mph
Minimum Sight Distance
Vertical curves	200'	150'	110'
Minimum Centerline Radius	230'	150'	90'
Minimum Superelevation Rate for Minimum Radius	.06 ft/ft	.04 ft/ft	.02 ft/ft
Maximum Grade, grades for 100' each way from intersection exceeding 5% may be reviewed by District Engineer for consideration. Grades less than 0.5% should not be used unless reviewed individually by the District Engineer to determine potential maintenance problems	9%	12%	18%
K = Rate of Vertical Curvature for Minimum Sight Distance
CREST	30	20	10
SAG	30	20	10
STOP	14	9	5
Formula for determination of length of vertical curve required to provide minimum site distance.
[L = KA]
L = Length of vertical curve in feet
K = Rate of vertical curvature in feet per percent of A
A = Algebraic difference in grades in percent
Minimum Cul-De-Sac Radius Right-of-Way
Curb and gutter section	45'	45'	45'
Shoulder section	50'	50'	50'
Minimum Cul -De-Sac Radius
Curb and gutter section	37' to G	37' to G	37' to G
Shoulder section * (see § 155.046)	35'	35'	35'
NOTES TO TABLE:
* - On cul-de-sacs, a maximum of two-tenths of a mile in length, 18 feet of pavement will be allowed (not including gutter). (See §§ 155.061, 155.066 and 155.069.) Cul-de-sac designs other than the "bulb" end design will be subject to the approval of th Division Engineer after review on an individual basis. See § 155.068 for several examples of minor residential cul-de-sac designs.
** - The minimum superelevation rates shown for the varying design speeds are for the minimum radii shown. For radii different from these, use the appropriate table from the 1994 Edition of AASHTO's Policy on Geometric Design of Highways and Streets for a desirable design. For a minimum design, the superelevation rate can be calculated from the simplified curve formula:
e = (v2) -f (15R)
where
e = superelevation rate in foot per foot
V = design speed in miles per hour
R = radius of curve in feet
f = side friction factor (See page 143 of the 1994 Policy on Geometric Design of Highways and Streets)
Short cul-de-sacs and dead end streets 1,500 feet or less in length may be accepted without superelevation.

 

(Ord. passed 1-1-2000)