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Unsignalized Intersections
Unsignalized Intersections Unsignalized Intersections
FHWA Safety Focus Areas FHWA Safety Focus Areas
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Safety at Unsignalized Intersections Safety at Unsignalized - - PowerPoint PPT Presentation
Safety at Unsignalized Intersections Safety at Unsignalized - - PowerPoint PPT Presentation
Safety at Unsignalized Intersections Safety at Unsignalized Intersections Unsignalized Intersections FHWA Safety Focus Areas FHWA Safety Focus Areas Unsignalized Intersections Unsignalized Intersections 2 National Statistics National
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Unsignalized Intersections Unsignalized Intersections
National Statistics National Statistics
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Unsignalized Intersections Unsignalized Intersections
National Statistics National Statistics
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Non-Intersections 79% Intersections 21%
There were 41,059 highway fatalities There were 41,059 highway fatalities in 2007. Where did they occur? in 2007. Where did they occur? About half of About half of all all crashes and crashes and half of all injury crashes half of all injury crashes
- ccur at intersections.
- ccur at intersections.
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Unsignalized Intersections Unsignalized Intersections
Intersection Fatalities Intersection Fatalities
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1,000 2,000 3,000 4,000 5,000 6,000 Arterial Collector Local Unknown
5,232 1,472 214 1,739
There were 8,657 intersection fatalities in 2007. There were 8,657 intersection fatalities in 2007. Where did they occur? Where did they occur? 39% in 39% in rural areas rural areas 61% in 61% in urban areas urban areas
Fatalities
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Unsignalized Intersections Unsignalized Intersections
Intersection Fatalities Intersection Fatalities
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Unsignalized Intersections Unsignalized Intersections
Intersection Safety Guidance Intersection Safety Guidance
- NCHRP Report 500 Volume 5
- Guide sheets
- Safety Strategies brochure
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Unsignalized Intersections Unsignalized Intersections
Typical Intersection Crash Types Typical Intersection Crash Types
- Right angle
- Rear end
- Left turn
- Sideswipe
- Pedestrian/bicycle
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Unsignalized Intersections Unsignalized Intersections
Crash Reduction Factors Crash Reduction Factors
- Quantitative results from
research or other studies
- Expected reduction in
crashes from implementation of a specific countermeasure
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Unsignalized Intersections Unsignalized Intersections 10
Angle Crashes Angle Crashes
Account for 53% of fatal crashes at unsignalized intersections
Clear sight triangles Improve awareness of intersection Apply access management Construct roundabouts Improve turn lane design
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Unsignalized Intersections Unsignalized Intersections 11
Angle Crashes Angle Crashes
Also:
- Close/relocate intersections
- Post appropriate speed limits
Acceleration Lane Through Lanes
Construct acceleration lanes
New alignment New alignment
Reduce/eliminate skew Targeted enforcement
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Unsignalized Intersections Unsignalized Intersections 12
Rear End Crashes Rear End Crashes
Install turn lanes Supplemental Supplemental
- verhead signing
- verhead signing
Provide shoulder bypass lanes
Account for 6% of fatal crashes at unsignalized intersections
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Unsignalized Intersections Unsignalized Intersections 13
Rear End Crashes Rear End Crashes
Also:
- Construct roundabouts
- Provide left-turn acceleration lanes
- Provide lighting
- Post appropriate speed limits
- Improve intersection awareness
Provide pavement Provide pavement markings markings Provide right-turn acceleration lanes
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Unsignalized Intersections Unsignalized Intersections 14
Left Turn Crashes Left Turn Crashes
Account for 8% of fatal crashes at unsignalized intersections
Improve turn lane design Implement turn restrictions Use indirect left turn treatments Also:
- Provide lighting
- Clear sight triangles
- Provide left turn acceleration lanes
- Construct roundabouts
- Close/relocate high-risk intersections
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Unsignalized Intersections Unsignalized Intersections 15
Sideswipe Crashes Sideswipe Crashes
Account for 2% of fatal crashes at unsignalized intersections
Provide lane assignment signing or marking Also:
- Provide right-turn acceleration
lanes Install pavement markings
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Unsignalized Intersections Unsignalized Intersections 16
Pedestrian/Bicycle Crashes Pedestrian/Bicycle Crashes
Account for 14% of fatal crashes at unsignalized intersections
Improve facilities Information and education Provide traffic calming
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Unsignalized Intersections Unsignalized Intersections 17
For More Information For More Information
- AASHTO Report 500 Series Volume 5
– http://safety.transportation.org/
- Manual on Uniform Traffic Control Devices
– http://mutcd.fhwa.dot.gov/
- Toolbox on Intersection Safety and Design
– http://www.ite.org/
- FHWA Office of Safety