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

Item No. | Item | Rural | Urban Item No. | Item | 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 3 | Typical Number of Lanes | 2 4 | Minimum Width of Travel Lanes (ft) | 9 | 11–122 | 10–113 5 | Minimum Width of Shoulders (ft) 4 | 2 | 5–85 | When used6 6 | Shoulder Type | Aggregate | Paved 7 | Minimum Width of Parking Lanes (where used) (ft) | N/A | 7―Residential 8―Industrial 8 | Minimum Width of Sidewalk (where used) (ft) 8 | (a) When offset from curb | N/A | 4 8 | (b) When adjacent to curb | N/A | 6 9 | Fore Slope (vertical–horizontal) | 1:37 | 1:3 7 | 1:4 | 1:3 10 | Back Slope (vertical–horizontal) | 1:2 | 1:3 | 1:2 11 | Pavement Cross Slope (%) | 2.5 12 | Minimum Stopping Sight Distance (ft) | 200 | 305 | 425 | 115 | 200 13 | Maximum Superelevation (%) | 108 | 4 14 | Minimum Radius (ft) 9, 10 14 | (a) With normal crown (-2.5% cross slope) | 7,585 | 11,625 | 16,700 | 100 | 325 14 | (b) With 2.5% superelevation | 1,930 | 3,250 | 5,000 | 85 | 250 14 | (c) With full superelevation | 250 | 450 | 700 | 80 | 235 15 | Maximum Grade (%)11 | 7 | 6 | 10 | 9 16 | Minimum Vertical Clearance (ft) | 15 17 | Minimum Clear Zone(ft) 17 | (a) From edge of through travel lane | 107 | Varies12 | 7―Shoulder facilities | 10―Shoulder facilities 17 | (b) From back of curb (when curb is used) | N/A | 1 (min)–6 (des) 18 | Bridge Design Live Load13 | AASHTO 19 | Minimum Width of Bridges (face to face of bridge rail at gutter line) | Traveled way plus 4' | Traveled14 way plus 6' | Traveled15, 16 way plus 8' | Traveled15, 16, way plus 8' 20 | Bridge End Treatment | Yes | 16