La. Admin. Code tit. 70 § I-1321

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

Section I-1321 - Minimum Design Guidelines for Urban and Suburban Collector Roads and Streets

Item No.	Item	Urban		Suburban1
		UC-1	UC-2	SC-1	SC-2	SC-3
1	Average Daily Traffic	N/A	N/A	N/A	N/A	N/A
2	Design Speed (mph)	30-40	45	40	45	50
3	Number of Lanes (minimum)	2-4	2-4	2-4	2-4	2-4
4	Width of Travel Lanes (ft)	11-12	122	11	11	11-122
5	Width of Shoulders (ft)
	(a) Inside on multilane facilities	N/A	N/A	N/A	N/A	43
	(b) Outside	82, 4	82,4	4-54	4-54	6, 85
6	Shoulder Type	Paved	Paved	Paved	Paved	Paved
7	Width of Parking Lanes (where used) (ft)	7-106	11	7-106	11	N/A
8	Width of Median on multilane facilities (ft)
	(a) Depressed	N/A	N/A	N/A	N/A	30
	(b) Raised	4 (min)-30 (des)	4 (min) -30 (des)	4 (min)-30 (des)	4 (min)-30 (des)	26
	(c) Two way left turn lane	11-14 typ.7	11-14 typ.7	11-14 typ.7	11-14 typ.7	N/A
9	Width of Sidewalk (minimum) (where used) (ft) 8
	(a) When offset from curb	4	4	4	4	4
	(b) When adjacent to curb	6	6	6	6	N/A
10	Fore Slope (vertical - horizontal)	1:3-1:49	1:3-1:49	1:4	1:4	1:4
11	Back Slope (vertical - horizontal)	1:310	1:3	1:3	1:3	1:3
12	Pavement Cross Slope (%)	2.5	2.5	2.5	2.5	2.5
13	Minimum Stopping Sight Distance (ft)	200 (30mph) 305 (40mph)	360	305	360	425
14	Maximum Superelevation (%)	4	4	4	4	6
15	Minimum Radius (ft)11, 12
	(a) With normal crown (-2.5% cross slope)	325(30mph) 700(40mph)	1,000	700	1,000	16,700
	(b) With 2.5% superelevation	250(30mph) 550(40mph)	750	550	750	4,400
	(c) With full superelevation	235(30mph) 500(40mph)	700	500	700	900
16	Maximum Grade (%)	9	8	7	6	6
17	Minimum Vertical Clearance (ft)13	15	15	15	15	15
18	Minimum Clear Zone(ft)
	(a) From edge of through travel lane	10	10	10	10	26 - 2814
	(b) Outside from back of curb (when curb is used)	1 (min)-6 (des)	6 (min)-8 (des)	1 (min)-6 (des)	6 (min)-8 (des)	17 - 1915
	(c) Median from back of curb (when curb is used)	1 (min)-6 (des)	1 (min)-8 des)	1 (min) -6 (des)	1 (min)-8(des)	13
19	Bridge Design Live Load16	AASHTO	AASHTO	AASHTO	AASHTO	AASHTO
20	Minimum Width of Bridges (face to face of bridge rail at gutter line)
	(a) Curbed facilities (without sidewalks)	Traveled17 way plus 8'	Traveled17 way plus 8'	Traveled 17 way plus 8'	Traveled17 way plus 8'	Roadway width
	(b) Shoulder facilities	Roadway width	Roadway width	Roadway width	Roadway width	Roadway width
21	Guardrail Required at Bridge Ends	17	17	17	17	Yes

La. Admin. Code tit. 70, § I-1321

Promulgated by the Department of Transportation and Development, Office of Highways/Engineering, LR 30:811 (April 2004), repromulgated LR 30:2337 (October 2004), amended LR 35:2846 (December 2009).

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