LAC 70:I.1301 – Minimum Design Guidelines for Rural Arterial Roads

Item No.	Item	Rural
		RA-1	RA-2	RA-3
1	Design Speed (mph)	50¹	60²	70
2	Number of Lanes (minimum)³	2	2	4
3	Width of Travel Lanes (ft)	11–12⁴	12	12
4	Width of Shoulders (minimum)(ft)
	(a) Two Lane	8⁵	8⁵	N/A
	(b) Divided facilities
	(1) Inside⁸	4	4	4⁶
	(2) Outside	8⁵	8⁵	8–10⁷
5	Shoulder Type	Aggregate (2' min paved)	Aggregate (2' min paved)	Paved Aggregate⁸ (2' min paved)
6	Parking Lane Width (ft)	N/A	N/A	N/A
7	Width of Median on Divided Facilities (ft)
	(a) Depressed	42–60	42-60	60
	(b) Raised	N/A	N/A	N/A
	(c) Two way left turn lane	N/A	N/A	N/A
8	Fore slope (vertical–horizontal)	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 (%)⁹	10	10	10
13	Minimum Radius (ft)¹⁰ (with full superelevation)	700	1,100	1,700
14	Maximum Grade (%)¹¹	4	3	3
15	Minimum Vertical Clearance (ft)¹²	16	16	16
16	Minimum Clear Zone(ft)(from edge of through travel lane)	20	30¹³	34
17	Bridge Design Live Load¹⁴	AASHTO	AASHTO	AASHTO
18	Width of Bridges (min) (face to face of bridge rail at gutter line) (ft)	Roadway width	Roadway width	Roadway width

Authority Note

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

Historical Note

HISTORICAL NOTE: Promulgated by the Department of Transportation and Development, Office of Highways/Engineering, LR 30:806 (April 2004), repromulgated LR 30:2332 (October 2004), amended LR 35:2840 (December 2009).