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 Statistics Unsignalized Intersections Unsignalized Intersections 3

National Statistics National Statistics There were 41,059 highway fatalities There were 41,059 highway fatalities in 2007. Where did they occur? in 2007. Where did they occur? Non-Intersections 79% Intersections 21% About half of all all crashes and crashes and About half of half of all injury crashes half of all injury crashes occur at intersections. occur at intersections. Unsignalized Intersections Unsignalized Intersections 4

Intersection Fatalities Intersection Fatalities There were 8,657 intersection fatalities in 2007. There were 8,657 intersection fatalities in 2007. Where did they occur? Where did they occur? 6,000 5,232 5,000 39% in 39% in rural areas rural areas 4,000 Fatalities 3,000 2,000 1,739 61% in 61% in 1,472 urban areas urban areas 1,000 214 0 Arterial Collector Local Unknown Unsignalized Intersections Unsignalized Intersections 5

Intersection Fatalities Intersection Fatalities Unsignalized Intersections Unsignalized Intersections 6

Intersection Safety Guidance Intersection Safety Guidance • NCHRP Report 500 Volume 5 • Guide sheets • Safety Strategies brochure Unsignalized Intersections Unsignalized Intersections 7

Typical Intersection Crash Types Typical Intersection Crash Types • Right angle • Rear end • Left turn • Sideswipe • Pedestrian/bicycle Unsignalized Intersections Unsignalized Intersections 8

Crash Reduction Factors Crash Reduction Factors • Quantitative results from research or other studies • Expected reduction in crashes from implementation of a specific countermeasure Unsignalized Intersections Unsignalized Intersections 9

Angle Crashes Angle Crashes Construct roundabouts Account for 53% of fatal crashes at unsignalized intersections Improve turn lane design Apply access management Clear sight triangles Improve awareness of intersection Unsignalized Intersections Unsignalized Intersections 10

Angle Crashes Angle Crashes Reduce/eliminate skew New alignment Targeted enforcement New alignment Construct acceleration lanes Also: • Close/relocate intersections • Post appropriate speed limits Through Lanes Acceleration Lane Unsignalized Intersections Unsignalized Intersections 11

Rear End Crashes Rear End Crashes Account for 6% of fatal crashes at unsignalized intersections Provide shoulder bypass lanes Install turn lanes Supplemental Supplemental overhead signing overhead signing Unsignalized Intersections Unsignalized Intersections 12

Rear End Crashes Rear End Crashes Provide right-turn acceleration lanes Provide pavement Provide pavement markings markings Also: • Construct roundabouts • Provide left-turn acceleration lanes • Provide lighting • Post appropriate speed limits • Improve intersection awareness Unsignalized Intersections Unsignalized Intersections 13

Left Turn Crashes Left Turn Crashes Account for 8% of fatal crashes at unsignalized intersections Use indirect left turn treatments Improve turn lane design Also: • Provide lighting • Clear sight triangles • Provide left turn acceleration lanes • Construct roundabouts • Close/relocate high-risk intersections Implement turn restrictions Unsignalized Intersections Unsignalized Intersections 14

Sideswipe Crashes Sideswipe Crashes Account for 2% of fatal crashes at unsignalized intersections Install pavement markings Provide lane assignment signing or marking Also: • Provide right-turn acceleration lanes Unsignalized Intersections Unsignalized Intersections 15

Pedestrian/Bicycle Crashes Pedestrian/Bicycle Crashes Improve facilities Account for 14% of fatal crashes at unsignalized intersections Information and education Provide traffic calming Unsignalized Intersections Unsignalized Intersections 16

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 – http://safety.fhwa.dot.gov/ Unsignalized Intersections Unsignalized Intersections 17