Components of a Road Safety Study

1
Common Sense Solutions for Intersection Safety
Problems

• Components of a Road Safety Study

2
Education Goals

• Understand the three phases of a road safety
  study.
• Understand the five different types of analysis
  performed during the site study phase of a road
  safety study.
• Understand the four parts of a Human Factors
  Analysis.

3
The Safety Study Process
Illustration courtesy of Hamilton Assoc.
4
Finding the Problem Areas

• Pre-Study Phase
• Data Collection
• Network Screening
• Site Selection

5
Finding The Problem Areas
6
Site Study Phase

• Kickoff Meeting
• Site Visit
• Geometric Analysis
• Collision Analysis
• Operational Analysis
• Conflict Analysis
• Human Factors Analysis

7
Geometric Analysis

• Contributing Factors
• Alignment of legs
• Skew of legs
• Sight distance obstructions
• Grade

8
Crash Analysis

• Requirements
• Analysis of crash reports
• Plot crashes
• Crash statistics

9
Operations Analysis

• Requirements
• Traffic turning movements
• Traffic volume data
• Signal timing
• Crash statistics

10
Conflict Analysis

• Requirements
• On site observer
• Record vehicle conflicts
• Rate by severity

11
Human Factors Analysis

• Review of the intersection
• from the drivers perspective
• VisibilityCan you see the sign or signal?
• ExpectancyDo you expect it to be there?
• ConsistencyIs it the same at other locations?
• Visual workloadCan you understand what it is?

12
Photo courtesy of Hamilton Assoc.
13
Report Phase

• REQUIREMENTS
• Identification of deficiencies
• Selection of Countermeasures

14
Post Report Phase

• Implementation
• Evaluation
• Recommendations for next study phase

15
Ask Questions, Understand More
Life is a succession of lessons which must be
lived to be understood. Ralph Waldo Emerson