GDOT, Keeping Georgia on the Move Georgia Department of Transportation

Table 4.5. Maximum Vertical Grades

Type of Terrain

Maximum Grade (%) for Specified Design Speed (mph)
15
20
25
30
35
40
45
50
55
60
65
70
75
80

Industrial Roadways

Level

Rolling

Mountainous

-

-

-

-

-

-

4

5

6

4

5

6

4

5

6

4

5

6

3

4

5

3

4

5

3

4

5

3

4

5

-

-

-

-

-

-

-

-

-

-

-

-

Local Rural Roads

Level

Rolling

Mountainous

9

12

17

8

11

16

7

11

15

7

10

14

7

10

13

7

10

12

7

9

11

6

8

10

6

7

10

5

6

-

-

-

-

-

-

-

-

-

-

-

-

-

Local Urban Streets

Level

Rolling

Mountainous

12

14

17

11

13

16

11

12

15

10

11

14

10

11

13

9

10

12

9

10

11

8

9

-

8

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

Rural Collectors

Level

Rolling

Mountainous

-

-

-

7

10

12

7

10

11

7

9

10

7

9

10

7

8

10

7

8

10

6

7

9

6

7

9

5

6

8

-

-

-

-

-

-

-

-

-

-

-

-

Urban Collectors

Level

Rolling

Mountainous

-

-

-

9

12

14

9

12

13

9

11

12

9

10

12

9

10

12

8

9

11

7

8

10

7

8

10

6

7

9

-

-

-

-

-

-

-

-

-

-

Rural Arterials

Level

Rolling

Mountainous

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

5

6

8

5

6

7

4

5

7

4

5

6

3

4

6

3

4

5

3

4

5

3

4

5

3

4

5

Urban Arterials

Level

Rolling

Mountainous

-

-

-

-

-

-

-

-

-

8

9

11

7

8

10

7

8

10

6

7

9

6

7

9

5

6

8

5

6

8

-

-

-

-

-

-

-

-

-

-

-

-

Rural and Urban Freeways (Limited Access Facilities)

Level

Rolling

Mountainous

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

4

5

6

4

5

6

3

4

6

3

4

5

3

4

5

3

4

-

3

4

-