La. Admin. Code tit. 70 § I-1305

Current through Register Vol. 50, No. 9, September 20, 2024

Section I-1305 - Minimum Design Guidelines for Freeways

Item No.	Item	Urban		Rural
		F-1	F-2	F-31
1	Design Speed (mph)	50	60	70
2	Level of Service	C3	C3	B 2
3	Number of Lanes (minimum)	4	4	4
4	Width of Travel Lanes (ft)	12	12	12
5	Width of Shoulders (ft)
	(a) Inside4	6	6	6
	(b) Outside5	10	10	10
6	Shoulder Type	Paved	Paved	Paved
7	Width of Median (minimum) (ft)
	(a) Depressed	50	68 (min)-100 (des)	72 (min)-100 (des)
	(b) Continuous barrier (4 lane)6	15	15	15
	Continuous barrier (6 lane)6	27	27	27
8	Fore Slope (vertical - horizontal)	1:4 to 1:6	1:6	1:6
9	Back Slope (vertical - horizontal)	1:4	1:4	1:4
10	Pavement Cross Slope (%)	2.5	2.5	2.5
11	Minimum Stopping Sight Distance (ft)	425	570	730
12	Maximum Superelevation (%)7	10	10	10
13	Minimum Radius (ft)8 (with 10% superelevation)	700	1,100	1,700
14	Maximum Grade (%)9	4	3	3
15	Minimum Vertical Clearance (ft)10	16	16	16
16	Width of Right-of-Way (ft)
	(a) Depressed median	As Needed	As Needed	Varies11
	(b) Median barrier	As Needed	As Needed	As Needed
	(c) Minimum from edge of bridge structure12	15-20	15-20	15-20
17	Bridge Design Live Load13	AASHTO	AASHTO	AASHTO
18	Minimum Width of Bridges (face to face of bridge rail at gutter line) (ft)	Roadway Width	Roadway Width	Roadway Width
19	Minimum Clear Zone(from edge of through travel lane)(ft)
	(a) 1:4 Fore slope	30	N/A	N/A
	(b) 1:6 Fore slope	22	32	34

La. Admin. Code tit. 70, § I-1305

Promulgated by the Department of Transportation and Development, Office of Highways/Engineering, LR 30:807 (April 2004), repromulgated LR 30:2333 (October 2004), amended LR 35:2841 (December 2009).

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