hampton roads regional safety study – 2013 update … · 2014. 1. 8. · hampton roads regional...
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1HAMPTON ROADS REGIONAL SAFETY STUDY – 2013 UPDATEPART I: CRASH TRENDS AND LOCATIONS
Presented by: Keith Nichols, PETransportation Technical Advisory Committee
January 8th, 2014
HAMPTON ROADS REGIONAL SAFETY STUDY – 2013 UPDATE
POTENTIAL FOR SAFETY IMPROVEMENT
2HAMPTON ROADS REGIONAL SAFETY STUDY – 2013 UPDATEPART I: CRASH TRENDS AND LOCATIONS
• In Part I of the Hampton Roads Regional Safety Study 2013 update, HRTPO staff analyzed the safety performance of each mile of freeway and of approximately 600 of the busiest intersections throughout the region.
• HRTPO staff reported the total number of crashes and Equivalent Property Damage Only (EPDO) Rate from 2009-2012 as safety performance measures.
• New methods and manuals are being introduced to improve safety performance measure reporting.
INTRODUCTION
3HAMPTON ROADS REGIONAL SAFETY STUDY – 2013 UPDATEPART I: CRASH TRENDS AND LOCATIONS
• In addition, predictive safety research has been conducted by the Virginia Center for Transportation Innovation and Research (VCTIR) for VDOT.
HIGHWAY SAFETY MANUAL
• The AASHTO Highway Safety Manual (HSM) is a recently released document that provides: • Methods and tools for considering
safety when making decisions related to roadway planning, design and operation.
• A quantitative approach to assess and predict the impacts of roadway safety countermeasures.
4HAMPTON ROADS REGIONAL SAFETY STUDY – 2013 UPDATEPART I: CRASH TRENDS AND LOCATIONS
IDENTIFYING CANDIDATE LOCATIONS FOR SAFETY IMPROVEMENTS
• Using the total number or rate of crashes to determine the most hazardous locations has weaknesses:• The relationship between the number of crashes and
traffic volumes is generally not linear.• The number of crashes at a specific location can vary
greatly from year to year• New research recommends determining the most
hazardous locations by instead looking at the difference between: • The number of observed crashes (“expected”), and • The typical number of crashes (“predicted”)
5HAMPTON ROADS REGIONAL SAFETY STUDY – 2013 UPDATEPART I: CRASH TRENDS AND LOCATIONS
EXPECTED CRASHES
• “Expected” crashes are calculated using the short-term observed crash totals (i.e. 24 crashes occurred over a 4-year period), adjusted to account for yearly variation and regression to the mean.
6HAMPTON ROADS REGIONAL SAFETY STUDY – 2013 UPDATEPART I: CRASH TRENDS AND LOCATIONS
PREDICTED CRASHES
• “Predicted” crashes are the typical number of crashes that would be found at a location for a given volume, facility type, etc.
• The number of “predicted” crashes can be estimated using Safety Performance Functions (SPFs), which are a function of a number of factors including:• AADT• Area Type• Facility type
= exp [a + (b x ln(Major AADT)) + (c x ln(Minor AADT))]Predicted single and multi-vehicle
crash frequency per year
• Segment length (freeways)• Control type (intersections)
SPF EXAMPLE FOR INTERSECTIONS
7HAMPTON ROADS REGIONAL SAFETY STUDY – 2013 UPDATEPART I: CRASH TRENDS AND LOCATIONS
Observed Crashes
Empirical Bayes Adjusted Expected Crashes
SPF Predicted Crashes
Potential for Safety Improvement
POTENTIAL FOR SAFETY IMPROVEMENT
• VCTIR refers to this difference as the Potential for Safety Improvement (PSI).
Source: VCTIR.POTENTIAL FOR SAFETY IMPROVEMENT
PSI = “Expected Crashes” – “Predicted Crashes”
8HAMPTON ROADS REGIONAL SAFETY STUDY – 2013 UPDATEPART I: CRASH TRENDS AND LOCATIONS
POTENTIAL FOR SAFETY IMPROVEMENT
• The locations selected in this report for further study are those freeway segments and intersections in Hampton Roads with the highest PSI (i.e. the greatest difference between the number of expected crashes and the number of predicted crashes).
9HAMPTON ROADS REGIONAL SAFETY STUDY – 2013 UPDATEPART I: CRASH TRENDS AND LOCATIONS
PSI – PENINSULA FREEWAYS
24
6
8
10HAMPTON ROADS REGIONAL SAFETY STUDY – 2013 UPDATEPART I: CRASH TRENDS AND LOCATIONS
PSI – SOUTHSIDE FREEWAYS
9
103
1
7
5
11HAMPTON ROADS REGIONAL SAFETY STUDY – 2013 UPDATEPART I: CRASH TRENDS AND LOCATIONS
PSI Rank Jurisdiction Facility Segment From Segment To Dir
PSI (Annual Expected Crashes - Predicted Crashes)
EPDO Crash Rate
Rank1 NOR I-64 NORTHAMPTON BLVD I-264 EB 126.67 32 HAM/NOR I-64/HRBT MALLORY ST OCEAN VIEW AVE EB 67.95 143 PORT/NOR I-264/DOWNTOWN TUNNEL EFFINGHAM ST I-464 EB 44.60 14 HAM/NOR I-64/HRBT MALLORY ST OCEAN VIEW AVE WB 42.62 185 NOR I-264 I-64 NEWTOWN RD/WCL VA. BEACH WB 38.63 96 NN I-64 YORKTOWN RD FORT EUSTIS BLVD EB 35.65 197 VB I-264 NEWTOWN RD/ECL NORFOLK WITCHDUCK RD EB 32.91 228 HAM I-64 ARMISTEAD AVE SETTLERS LANDING RD EB 30.89 179 SUF/NN I-664/MMMBT COLLEGE DR TERMINAL AVE NB 30.72 4710 NOR/VB I-64 I-264 INDIAN RIVER RD WB 28.64 29
PSI Rank Jurisdiction Facility Segment From Segment To Dir
PSI (Annual Expected Crashes - Predicted Crashes)
EPDO Crash Rate
Rank1 NOR I-64 NORTHAMPTON BLVD I-264 EB 126.67 32 HAM/NOR I-64/HRBT MALLORY ST OCEAN VIEW AVE EB 67.95 143 PORT/NOR I-264/DOWNTOWN TUNNEL EFFINGHAM ST I-464 EB 44.60 14 HAM/NOR I-64/HRBT MALLORY ST OCEAN VIEW AVE WB 42.62 185 NOR I-264 I-64 NEWTOWN RD/WCL VA. BEACH WB 38.63 96 NN I-64 YORKTOWN RD FORT EUSTIS BLVD EB 35.65 197 VB I-264 NEWTOWN RD/ECL NORFOLK WITCHDUCK RD EB 32.91 228 HAM I-64 ARMISTEAD AVE SETTLERS LANDING RD EB 30.89 179 SUF/NN I-664/MMMBT COLLEGE DR TERMINAL AVE NB 30.72 4710 NOR/VB I-64 I-264 INDIAN RIVER RD WB 28.64 29
PSI - FREEWAYS
Source: HRTPO analysis using VCTIR methodology. Data included in this table represents the years 2009-2012.
EPDO = Equivalent Property Damage Only.
FREEWAYS WITH THE HIGHEST DIFFERENCE BETWEEN EXPECTED AND PREDICTED CRASHES
12HAMPTON ROADS REGIONAL SAFETY STUDY – 2013 UPDATEPART I: CRASH TRENDS AND LOCATIONS
PSI – PENINSULA INTERSECTIONS
5 3
27
8
13HAMPTON ROADS REGIONAL SAFETY STUDY – 2013 UPDATEPART I: CRASH TRENDS AND LOCATIONS
PSI - SOUTHSIDE INTERSECTIONS
9 6
1
10
4
14HAMPTON ROADS REGIONAL SAFETY STUDY – 2013 UPDATEPART I: CRASH TRENDS AND LOCATIONS
PSI Rank Jurisdiction Major Road Minor Road
PSI (Annual Expected Crashes - Predicted Crashes)
Annual Number of Crashes
Rank
EPDO Crash Rate Rank
1 VB Holland Rd Rosemont Rd 27.51 1 12 HAM HRC Pkwy Big Bethel Rd 22.80 3 53 HAM Mercury Blvd Power Plant Pkwy/Todds Ln 20.66 2 94 VB First Colonial Rd Va Beach Blvd 18.88 6 205 NN Mercury Blvd Jefferson Ave 16.71 4 106 VB General Booth Blvd Dam Neck Rd 13.58 5 457 HAM Armistead Ave LaSalle Ave 12.72 27 128 NN J Clyde Morris Blvd Diligence Dr 12.68 18 29 VB Princess Anne Rd Dam Neck Rd 11.69 7 3210 VB Lynnhaven Pkwy Independence Blvd 11.14 22 2811 HAM Mercury Blvd Cunningham Dr 10.91 14 2112 HAM Mercury Blvd Coliseum Dr 9.85 10 4813 NOR Chesapeake Blvd Norview Ave/Sewells Point Rd 9.27 38 1414 HAM Todds Ln Big Bethel Rd 9.05 47 1615 NOR Little Creek Rd Chesapeake Blvd 8.77 24 3316 PORT George Washington Hwy Victory Blvd 8.72 31 617 CHES Battlefield Blvd Great Bridge Blvd/Kempsville Rd 8.22 25 4118 VB Lynnhaven Pkwy Holland Rd 8.17 26 9419 NN Warwick Blvd Denbigh Blvd 7.10 23 5220 VB Va Beach Blvd Great Neck Rd/London Bridge Rd 7.02 15 97
PSI Rank Jurisdiction Major Road Minor Road
PSI (Annual Expected Crashes - Predicted Crashes)
Annual Number of Crashes
Rank
EPDO Crash Rate Rank
1 VB Holland Rd Rosemont Rd 27.51 1 12 HAM HRC Pkwy Big Bethel Rd 22.80 3 53 HAM Mercury Blvd Power Plant Pkwy/Todds Ln 20.66 2 94 VB First Colonial Rd Va Beach Blvd 18.88 6 205 NN Mercury Blvd Jefferson Ave 16.71 4 106 VB General Booth Blvd Dam Neck Rd 13.58 5 457 HAM Armistead Ave LaSalle Ave 12.72 27 128 NN J Clyde Morris Blvd Diligence Dr 12.68 18 29 VB Princess Anne Rd Dam Neck Rd 11.69 7 3210 VB Lynnhaven Pkwy Independence Blvd 11.14 22 2811 HAM Mercury Blvd Cunningham Dr 10.91 14 2112 HAM Mercury Blvd Coliseum Dr 9.85 10 4813 NOR Chesapeake Blvd Norview Ave/Sewells Point Rd 9.27 38 1414 HAM Todds Ln Big Bethel Rd 9.05 47 1615 NOR Little Creek Rd Chesapeake Blvd 8.77 24 3316 PORT George Washington Hwy Victory Blvd 8.72 31 617 CHES Battlefield Blvd Great Bridge Blvd/Kempsville Rd 8.22 25 4118 VB Lynnhaven Pkwy Holland Rd 8.17 26 9419 NN Warwick Blvd Denbigh Blvd 7.10 23 5220 VB Va Beach Blvd Great Neck Rd/London Bridge Rd 7.02 15 97
PSI - INTERSECTIONS
Source: HRTPO analysis using HSM methodology. Data included in this table represents the years 2009-2012.
EPDO = Equivalent Property Damage Only.
INTERSECTIONS WITH THE HIGHEST DIFFERENCE BETWEEN EXPECTED AND PREDICTED CRASHES
15HAMPTON ROADS REGIONAL SAFETY STUDY – 2013 UPDATEPART I: CRASH TRENDS AND LOCATIONS
NEXT STEPS
• HRTPO staff will analyze and recommend safety improvements for those locations with the highest PSI as shown in this presentation using:• Intersection summaries• Collision Diagrams• Site Observations• Analysis of Possible
Countermeasures
16HAMPTON ROADS REGIONAL SAFETY STUDY – 2013 UPDATEPART I: CRASH TRENDS AND LOCATIONS
NEXT STEPS
• Part II of this study will also include:• Efforts to Improve Roadway
Safety (Statewide Highway Safety Plan, HSIP, educational and enforcement programs, etc.)
• General Crash Countermeasures• Next steps
17HAMPTON ROADS REGIONAL SAFETY STUDY – 2013 UPDATEPART I: CRASH TRENDS AND LOCATIONS
Presented by: Keith Nichols, PETransportation Technical Advisory Committee
January 8th, 2014
HAMPTON ROADS REGIONAL SAFETY STUDY – 2013 UPDATE
POTENTIAL FOR SAFETY IMPROVEMENT