1. HW 7b: HSM Practitioner’s Guider for Two-Lane Rural Highways Workshop
Safety and Operational Effects of Geometric Design Features for Two-Lane Rural Highways Workshop
May 2009
Exercise III – US 52 from Sageville to Holy Cross – Prediction of Safety Performance for Intersections
Session #7 – Exercise III – US 52 in Iowa (west of DuBuque and the Mississippi River) – Prediction of Safety Peformance for Intersections and Comparison to Substantive Safety Performance
Session 7 – Exercise III - Intersections

2. Exercise III – US 52 from Sageville to Holy Cross
Safety and Operational Effects of Geometric Design Features for Two-Lane Rural Highways Workshop
May 2009
Exercise III – US 52 from Sageville to Holy Cross
Learning Outcomes:
Select Intersection Crashes out of Total Crashes
Apply SPF Base Model equations for prediction of crash frequency performance
Compare predicted crash frequency to Substantive Safety performance
Learning Objectives for Session #9 – Exercise III – Prediction of safety performance for Intersections on US 52
Session 7 – Exercise III - Intersections

3. Exercise III – US 52 from Sageville to Holy Cross
Safety and Operational Effects of Geometric Design Features for Two-Lane Rural Highways Workshop
May 2009
Exercise III – US 52 from Sageville to Holy Cross
Session 7 – Exercise III - Intersections

4. Exercise III – US 52 from Sageville to Holy Cross
Safety and Operational Effects of Geometric Design Features for Two-Lane Rural Highways Workshop
May 2009
Exercise III – US 52 from Sageville to Holy Cross
Session 7 – Exercise III - Intersections

5. HSM Practicitioner's Guide for Two-Lane Rural Highways Workshop
Exercise III: US 52 from Sageville to Holy Cross – Segments/Grade/Curves
August 2010
LOCATION
NUMBER
On Roadway Segments 63
Within Intersection 16
Intersection Related 1
On-Grades 3
On Curves 39
Total
122
Crashes by location
Session 2 – Exercise I

6. Exercise III – US 52 from Sageville to Holy Cross
Safety and Operational Effects of Geometric Design Features for Two-Lane Rural Highways Workshop
May 2009
Exercise III – US 52 from Sageville to Holy Cross
Stop-Controlled Intersections on US 52: (AADTmaj = 2,500)
Station
Location
Type
Side Road ADT
Predicted Crashes
Skew
Crashes x CMF
107
East of D
3-leg
450
15 deg
126
West of D
250
5 deg
262
East of F
70 deg
559 F
4-leg
300
0 deg
TOTAL ?
Complete the table: Predicted crashes of the four stop-controlled intersections and their AMF for skew. Sum the results to obtain the total number of predicted crashes for the four intersections.
Session 7 – Exercise III - Intersections

7. Exercise III – US 52 from Sageville to Holy Cross
Safety and Operational Effects of Geometric Design Features for Two-Lane Rural Highways Workshop
May 2009
Exercise III – US 52 from Sageville to Holy Cross
Compute the predicted crashes for the four (4) intersections on US 52
Compare the Actual Crash Frequency to the Predicted Crash Frequency per year for the Intersections
Discussion
Pause at this slide; continue on when participants have worked on the exercise.
Use Worksheet Exercise III
Session 7 – Exercise III - Intersections

8. Exercise III – US 52 from Sageville to Holy Cross
Safety and Operational Effects of Geometric Design Features for Two-Lane Rural Highways Workshop
May 2009
Exercise III – US 52 from Sageville to Holy Cross
From the US 52 corridor crash information, perform the following:
Compare the actual crash frequency per year with the Predicted Crash Frequency performance for the Intersections
Actual Crash Frequency = __ crashes / __ years
= ___ crashes / year
Predicted Intersection
Crash Freuency = ____ crashes/year
Session 7 – Exercise III - Intersections

9. Exercise III – US 52 from Sageville to Holy Cross
Safety and Operational Effects of Geometric Design Features for Two-Lane Rural Highways Workshop
May 2009
Exercise III – US 52 from Sageville to Holy Cross
Learning Outcomes:
Selected Intersection Crashes out of Total Crashes
Applied SPF Base Model equations for prediction of crash frequency performance
Compared predicted crash frequency to Substantive Safety performance
Learning Objectives for Session #9 – Exercise III – Prediction of safety performance for Intersections on US 52
Session 7 – Exercise III - Intersections

10. Questions and Discussion
HSM Applications to Two-Lane Rural Highways
Safety and Operational Effects of Geometric Design Features for Two-Lane Rural Highways Workshop
May 2009
Questions and Discussion
Session 7 – Exercise III - Intersections