La. Admin. Code tit. 70 § I-1313

Current through Register Vol. 50, No. 11, November 20, 2024

Section I-1313 - Minimum Design Guidelins for Rural Collector Roads

Item No.	Item	Rural
		RC-1	RC-2	RC-3
1	Average Daily Traffic 1	Under 400	400-2000	Over 2000
2	Design Speed (mph)	40-602	50-602	60
3	Number of Lanes	2	2	2-43
4	Width of Travel Lanes (ft)	11	11-124	12
5	Width of Shoulders (ft)
	(a) Inside on multilane facilities	N/A	N/A	4
	(b) Outside	25	4-56	8
6	Shoulder Type	Paved	Aggregate (2' min paved)	Aggregate (2' min paved)7
7	Width of Parking Lanes (ft)	N/A	N/A	N/A
8	Width of Median on multilane facilities (ft)
	(a) Depressed	N/A	N/A	42-60
	(b) Raised	N/A	N/A	N/A
	(c) Two way left turn lane	N/A	N/A	N/A
9	Width of Sidewalk (minimum) (ft)
	(a) Offset from curb	N/A	N/A	N/A
	(b) Adjacent to curb	N/A	N/A	N/A
10	Fore Slope (vertical-horizontal)	1:4	1:4	1:6
11	Back Slope (vertical-horizontal)	1:48	1:4	1:4
12	Pavement Cross Slope (%) 8	2.5	2.5	2.5
13	Stopping Sight Distance (ft)	305 (40 mph) 425 (50 mph) 570 (60 mph)	425 (50 mph) 570 (60 mph)	570
14	Maximum Superelevation (%)9	10	10	10
15	Minimum Radius (ft) 10 (with full superelevation)	45011	70012	1,100
16	Maximum Grade (%)	7 (40 mph) 6 (50 mph) 5 (60 mph)	6 (50 mph) 5 (60 mph)	5
17	Minimum Vertical Clearance (ft)13	15	15	15
18	Minimum Clear Zone (ft) (from edge of through travel lane)	10, 14, 2414	26 (50 mph) 32 (60 mph)	30
19	Bridge Design Live Load15	AASHTO	AASHTO	AASHTO
20	Minimum Width of Bridges (face to face of bridge rail at gutter line) (ft)	30	Roadway width	Roadway width

La. Admin. Code tit. 70, § I-1313

Promulgated by the Department of Transportation and Development, Office of Highways/Engineering, LR 30:809 (April 2004), repromulgated LR 30:2335 (October 2004), amended LR 35:2844 (December 2009).

AUTHORITY NOTE: Promulgated in accordance with R.S. 48:35(C).