LAC 70:I.1305. Minimum Design Guidelines for Freeways

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