LAC 70:I.1309 – Minimum Design Guidelines for Local Roads and Streets

Item No.	Item	Rural	Urban
		RL-1	RL-2	RL-3	UL-1	UL-2
1	Design Speed (mph)¹	30	40	50	20	30
2	Average Daily Traffic	0–250	250–400	Over 400	N/A	N/A
3	Typical Number of Lanes	2	2	2	2	2
4	Minimum Width of Travel Lanes (ft)	9	9	11–12²	10–11³	10–11³
5	Minimum Width of Shoulders (ft)⁴	2	2	5–8⁵	When used⁶	When used⁶
6	Shoulder Type	Aggregate	Aggregate	Aggregate	Paved	Paved
7	Minimum Width of Parking Lanes (where used) (ft)	N/A	N/A	N/A	7―Residential 8―Industrial	7―Residential 8―Industrial
8	Minimum Width of Sidewalk (where used) (ft)
	(a) When offset from curb	N/A	N/A	N/A	4	4
	(b) When adjacent to curb	N/A	N/A	N/A	6	6
9	Fore Slope (vertical–horizontal)	1:3⁷	1:3 ⁷	1:4	1:3	1:3
10	Back Slope (vertical–horizontal)	1:2	1:2	1:3	1:2	1:2
11	Pavement Cross Slope (%)	2.5	2.5	2.5	2.5	2.5
12	Minimum Stopping Sight Distance (ft)	200	305	425	115	200
13	Maximum Superelevation (%)	10⁸	10⁸	10⁸	4	4
14	Minimum Radius (ft)^{9, 10}
	(a) With normal crown (-2.5% cross slope)	7,585	11,625	16,700	100	325
	(b) With 2.5% superelevation	1,930	3,250	5,000	85	250
	(c) With full superelevation	250	450	700	80	235
15	Maximum Grade (%)¹¹	7	7	6	10	9
16	Minimum Vertical Clearance (ft)	15	15	15	15	15
17	Minimum Clear Zone(ft)
	(a) From edge of through travel lane	10⁷	10⁷	Varies¹²	7―Shoulder facilities	10―Shoulder facilities
	(b) From back of curb (when curb is used)	N/A	N/A	N/A	1 (min)–6 (des)	1 (min)–6 (des)
18	Bridge Design Live Load¹³	AASHTO	AASHTO	AASHTO	AASHTO	AASHTO
19	Minimum Width of Bridges (face to face of bridge rail at gutter line)	Traveled way plus 4'	Traveled way plus 4'	Traveled¹⁴ way plus 6'	Traveled^{15, 16} way plus 8'	Traveled^{15, 16,} way plus 8'
20	Bridge End Treatment	Yes	Yes	Yes	¹⁶	¹⁶

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 30:808 (April 2004), repromulgated LR 30:2334 (October 2004), amended LR 35:2843 (December 2009).