HSM Practitioner’s Guider for Two-Lane Rural Highways Workshop

Exercise IV – US 52 from Sageville to Holy Cross – Group Exercise

- Session #8

8-1

Exercise IV: US 52 from Sageville to Holy Cross

Learning Outcomes:► Compute combined predicted safety performance of x-section, grade, curvature, and intersections

►Compare predicted safety performance to actual safety performance

► Identify greatest safety shortfall

► Identify priorities for improvement

8-2

8-3

1996 - 2000

8-4

Exercise IV: US 52 from Sageville to Holy Cross – Segments/Grade/Curves

LOCATION NUMBER

On Roadway Segments

63

Within Intersection 16

Intersection Related 1

On-Grades 3

On Curves 39

Total 122

Crashes by

location

8-5

Exercise I – US 52 from Sageville to Holy Cross

Length: 13.0 miles AADT: 2,500 Lane Width: 11 feet Shoulders:

Paved 0 feetGravel 4 feet

Hazard Rating: 5 Driveways: 91 on level tangent segmentsTotal Length of Curves = 4,826 ft or 0.914 mi Total Length of Grades = 13,400 ft or 2.54 mi

Geometric Information:

8-6

Exercise I – US 52 from Sageville to Holy CrossGeometric Information Grades:

Grade Section # % Grade Length in ft

1 5.6% 200

2 3.95 450

3 3.875 300

4 6 3200

5 5.2 450

6 5.2 450

7 5 700

8 5.4 350

9 3.05 400

10 5 900

11 5.9 1950

12 5 1700

13 6 1050

14 3.9 1150

15 4.8 150

Total Length = 13,400 feet or 2.54 miles

3%< All Grades <6%

8-7

Exercise II: US 52 from Sageville to Holy Cross

Geometric Information Curves:

Curve # Delta Degree Radius Length

1 104 deg 8 deg 50’ 670.15 ft 1,225.5 ft

2- “A” 104 deg 33’ 9 deg 836.6 ft 1162 ft

3- “B” 63 deg 56’ 12 deg 477.5 ft 532.8 ft

4- “C” 67 deg 04’ 12 deg 477.5 ft 558.9 ft

5- “D” 42 deg 15’ 12 deg 477.5 ft 352 ft

6- “E” 62 deg 58’ 12 deg 477.5 ft 524.8 ft

7- “F” 28 deg 10’ 6 deg 955 ft 469.4 ft

Total Length = 4,826 feet8-8

Exercise III – US 52 from Sageville to Holy Cross

Intersections on US 52: (AADTmaj = 2500)

Station Location Type Side Road ADT

Predicted Crashes

Skew Crashes x CMF

107 East of D T 450 15 deg

126 West of D T 250 5 deg

262 East of F T 450 70 deg

559 F + 300 0 deg

TOTAL ?

8-9

Exercise IV: US 52 from Sageville to Holy Cross

1. Compute the combined predicted safety performance (x-section + curves + intersections) and compare to actual safety record

2. Identify priorities areas for improvements

Discussion

Use Worksheet Exercise IV

8-10

Exercise IV – US 52 from Sageville to Holy Cross

From the US 52 corridor crash information, perform the following tasks:

2. Compute the combined predicted crash frequency performance (x-section + curves + intersections) and compare to actual crash record- Where is the greatest safety shortfall?

a. Lane and Shoulder Widthb. Driveway Densityc. Roadside Designd. Curvese. Intersections

8-11

From the US 52 corridor crash information, perform the following tasks:2. Identify priorities as to improvements

- where is the greatest shortfall (at 2,500 AADT)?

a. Lane and Shoulder Width (yes/no) (___%)

c. Roadside Design (yes/no) (____%)

d. Curves (yes/no) (___%)

e. Intersections (yes/no) (___%)

b. Driveway Density (yes/no) (___%)

Exercise IV – US 52 from Sageville to Holy Cross

8-12

Learning Outcomes:

► Computed combined predicted safety performance of x-section, grade, curvature, and intersections

►Compared predicted safety performance to actual safety performance

► Identified greatest safety shortfall

► Identified priorities for improvement

Exercise IV – US 52 from Sageville to Holy Cross

8-13

Safety Effects Calculations Rural Two-Lane Roads

CONCERNS:

GOOD NEWS:

Too Time Consuming for Calculations and Organizing Results?

Excel spreadsheet facilitates calculations and delivers results in an organized format!

8-14

Questions and Discussion

HSM Practitioner’s Guider for Two-Lane Rural Highways Workshop

8-15