overview of systemic approach to safety · pedestrian/bicycle 87 22% 60 15% 84 20% 100 19% ......
TRANSCRIPT
NACE/FHWA Local Road Safety Plan Pilot
December 2018 Workshop 1
Overview of
Systemic Approach to Safety
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Example: Fatal Crash Locations
Source: NHTSA (https://cdan.nhtsa/gov/stsi.htm#)
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201420152016
NACE/FHWA Local Road Safety Plan Pilot
December 2018 Workshop 2
Crash Type2012 2013 2014 2015
# % # % # % # %
Roadway Departure 243 60% 247 62% 252 59% 290 56%
Pedestrian/Bicycle 87 22% 60 15% 84 20% 100 19%
Intersection 98 24% 110 27% 131 31% 160 31%
TOTAL 403 401 429 516
Example: Major Fatal Crash Types in Washington by FHWA Focus Area
Source: FHWA ‐ https://rspcb.safety.fhwa.dot.gov/Dashboard/Default.aspx
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Systemic Safety Project Selection
1. Systemic Process
2. Balance Funds
3. Evaluate Effectiveness
https://safety.fhwa.dot.gov/systemic/fhwasa13019/sspst.pdf
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FHWA’s Systemic Safety Tool
NACE/FHWA Local Road Safety Plan Pilot
December 2018 Workshop 3
Element 1
Systemic Safety Planning Process
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Systemic Safety Planning Process
Step 1
Step 2
Step 3
Step 4
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NACE/FHWA Local Road Safety Plan Pilot
December 2018 Workshop 4
Systemic Safety Planning Process
• Step 1: Identify…–Focus Crash Types
–Focus Facility Types
–Risk Factors
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What we mean by “focus crash type”
Crash type representing greatest number of severe crashes across roadway system…
… provides greatest potential to reduce fatalities and severe injuries
• Road Departure
• Intersection
• Pedestrian
• Speeding
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NACE/FHWA Local Road Safety Plan Pilot
December 2018 Workshop 5
Task 1: Select Focus Crash Types
• Systemwide analysis
• Strategic Safety Plans
• Regional and jurisdictional analyses
–May differ from statewide needs
9https://www.maxpixel.net/Accident‐Broken‐Auto‐Damage‐Vehicle‐Total‐Damage‐1409006
Task 1: Select Focus Crash Types
Fatal and Severe Injury Crashes (2007‐2011)Percent by Jurisdiction
Emphasis AreaStatewide114,592 mi
State15,486 mi
County19,938 mi
City, Town, Village76,735 mi
Total Fatal/Serious Injury 100% 63,443 31% 19,819 10% 6,572 45% 28,597
Pedestrian 19% 11,786 9% 1,860 6% 421 28% 8,122
Bicycle 5% 3,390 3% 518 3% 187 8% 2,414
Heavy Vehicle 5% 3,123 6% 1,266 4% 234 4% 1,051
Road Departure 26% 16,668 30% 5,985 44% 2,892 18% 5,128
Intersection 41% 25,791 25% 5,033 30% 1,957 64% 18,270
Head‐on and Sideswipe 5% 3,071 7% 1,439 7% 490 3% 887
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NACE/FHWA Local Road Safety Plan Pilot
December 2018 Workshop 6
What we mean by “focus facility”
Facility type where focus crash type most frequently occurs
• Rural, Two‐Lane Highways
• Urban, Signalized Intersections
• Horizontal Curves
• Rural, Thru‐STOP Intersections
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Task 2: Select Focus Facilities
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5 years, Severe Roadway Departure
State System4,400 crashes
Urban1,900 crashes
Undivided1,102
Divided798
2 Lanes897
3 Lanes28
4 Lanes170
5‐6 Lanes7
< = 25 mph2
30‐35 mph195
40‐50 mph363
55+ mph336
Unknown1
< = 25 mph7
Rural2,512 crashes
Undivided2,165
Divided375
1 Lane1
2 Lanes2,090
3 Lanes35
4 Lanes39
30‐35 mph163
40‐50 mph281
55+ mph1,637
Unknown2
Rural2,500 crashes
Urban1,900 crashes
NACE/FHWA Local Road Safety Plan Pilot
December 2018 Workshop 7
What we mean by “risk factor”
Characteristics associated with locations where targeted crash types occur
• Volume
• Alignment
• Intersection Control
• Presence of Shoulders
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http://www.creative‐commons‐images.com/highway‐signs/r/risk.html
Potential Risk Factors
Roadway features:
• Lane width
• Shoulder width / type
• Median width / type
• Horizontal curvature
• Pavement condition / friction
• Roadside features– Sideslope design
– Clear zone
• Driveway density
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NACE/FHWA Local Road Safety Plan Pilot
December 2018 Workshop 8
Potential Risk Factors
Intersection features:
• Traffic control
• Turn lanes
• Skew angle
• Sight distance
• Presence of horizontal curve
• Railroad crossing
• Type of development (e.g., commercial)
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Potential Risk Factors
Pedestrian‐related features:
• Traffic control
• Sidewalk presence
• Crosswalk presence
• Crossing distance
• Adjacent land uses
• Lighting
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NACE/FHWA Local Road Safety Plan Pilot
December 2018 Workshop 9
Potential Risk Factors
Other general features:
• Traffic volume
• Speed
– Posted, operating
17Source: Seattle DOT
Descriptive Statistics Analysis
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23% 25%
8%
44%
85%
38%
20%
5%12%
88%
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
Narrow Clearzone Passing Lane Street Lighting Paved Shoulder Narrow Shoulder (< 3 feet)
Percent
Presence of Potential Risk Factor
Potential Risk Factors for Rural Lane Departure Crashes
Percent of System With Potential Risk Factor
Percent of Severe Lane Departure Crashes Where Potential Risk Factor is Present
NACE/FHWA Local Road Safety Plan Pilot
December 2018 Workshop 10
Descriptive Statistics Analysis
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0%
5%
10%
15%
20%
25%
30%
35%
40%
45%
50%
Percent
Vehicles Per Day
Daily Traffic Volume
Percent of Severe Run Off Road Crashes Percent of Severe Across Centerline Crashes
Percent of Miles
Data Sources
• Crash data– Law enforcement– State or local database– FARS
• Roadway data– State or local database– Video logs– Online aerial imagery– Windshield surveys
• Exposure data (AADT)– State or local database– Traffic counts
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Where do these data come from in your jurisdiction?
NACE/FHWA Local Road Safety Plan Pilot
December 2018 Workshop 11
Reasons for Systemic
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Systemic Approach to SafetyUsing Risk to Drive Action
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Source: https://safety.fhwa.dot.gov/systemic/
NACE/FHWA Local Road Safety Plan Pilot
December 2018 Workshop 12
Tool Demo
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24
Intersection
4 (17%)
Wet Dry Wet Dry Wet Dry Wet Dry
0 (0%) 1 (100%) 1 (14%) 6 (86%) 2 (20%) 8 (80%) 0 (0%) 2 (100%)
Non‐Intersection
20 (83%)
County Roads
24 Fatal and Serious Injury, Roadway Departure Crashes
2 (16%)
Day Night
1 (12%) 7 (88%)
Day
10 (84%)
Curve Tangent
12 (60%)8 (40%)
Night
NACE/FHWA Local Road Safety Plan Pilot
December 2018 Workshop 13
25
Intersection4 (17%)
Wet Dry Wet Dry Wet Dry Wet Dry8 (80%) 2 (20%) 0 (0%) 2 (100%) 0 (0%) 1 (100%) 1 (14%) 6 (86%)
12 (60%) 8 (40%)
County Roads
24 Fatal and Serious Injury, Roadway Departure Crashes
Non‐Intersection20 (83%)
Curve Tangent
Day Night Day Night10 (84%) 2 (16%) 1 (12%) 7 (88%)