04-10-2014, 12:32 PM

Input:

Y: speed of vehicle or design speed (mi/hr)

X: grade of the road (i.e. for 1% grade enter as 1)

Output:

X: Stopping Sight Distance (in feet)

Formula used:

SSD = 55/15 * V + 1.075*V^2/(11+.32*G)

Assumptions:

* Total reaction time is 2.5 seconds. The deceleration rate of the vehicle is 11 ft/s^2. Both values are recommended by the AASHTO (American Association of State Highway and Transportation Officials).

Program:

S01 LBL S

S02 0.32

S03 *

S04 11.2

S05 +

S06 1/x

S07 1.075

S08 *

S09 x<>y

S10 ENTER

S11 R-down

S12 x^2

S13 *

S14 R-up

S15 55

S16 *

S17 15

S18 ÷

S19 +

S20 RTN

Size: 54.0

Checksum: 2343

Examples:

Input:

Y: 65 (V)

X: 2 (G)

Result (Fix 4): 621.9376 ft

Input:

Y: 35 (V)

X: -4 (G)

Result: 261.0828

Reference:

Source: Goswami, Indramil Ph.D. P.E. "All In One Civil Engineering PE Breadth and Depth Exam Guide" 2nd Edition. McGraw Hill: 2012

Y: speed of vehicle or design speed (mi/hr)

X: grade of the road (i.e. for 1% grade enter as 1)

Output:

X: Stopping Sight Distance (in feet)

Formula used:

SSD = 55/15 * V + 1.075*V^2/(11+.32*G)

Assumptions:

* Total reaction time is 2.5 seconds. The deceleration rate of the vehicle is 11 ft/s^2. Both values are recommended by the AASHTO (American Association of State Highway and Transportation Officials).

Program:

S01 LBL S

S02 0.32

S03 *

S04 11.2

S05 +

S06 1/x

S07 1.075

S08 *

S09 x<>y

S10 ENTER

S11 R-down

S12 x^2

S13 *

S14 R-up

S15 55

S16 *

S17 15

S18 ÷

S19 +

S20 RTN

Size: 54.0

Checksum: 2343

Examples:

Input:

Y: 65 (V)

X: 2 (G)

Result (Fix 4): 621.9376 ft

Input:

Y: 35 (V)

X: -4 (G)

Result: 261.0828

Reference:

Source: Goswami, Indramil Ph.D. P.E. "All In One Civil Engineering PE Breadth and Depth Exam Guide" 2nd Edition. McGraw Hill: 2012