HAMPTON ROADS REGIONAL SAFETY STUDY – 2013 UPDATE … · 2014. 1. 8. · HAMPTON ROADS REGIONAL SAFETY STUDY – 2013 UPDATE 1 PART I: CRASH TRENDS AND LOCATIONS Presented by: Keith

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


• 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


• 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.


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”)


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.


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


Observed Crashes

Empirical Bayes Adjusted Expected Crashes

SPF Predicted Crashes

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”



• 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).


PSI – PENINSULA FREEWAYS

24

6

8


PSI – SOUTHSIDE FREEWAYS

9

103

1

7

5


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


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


PSI – PENINSULA INTERSECTIONS

5 3

27

8


PSI - SOUTHSIDE INTERSECTIONS

9 6

1

10

4


PSI Rank Jurisdiction Major Road Minor Road


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


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


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


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


Presented by: Keith Nichols, PETransportation Technical Advisory Committee

January 8th, 2014

HAMPTON ROADS REGIONAL SAFETY STUDY – 2013 UPDATE


Documents

HAMPTON ROADS REGIONAL SAFETY STUDY – 2013 UPDATE … · 2014. 1. 8. · HAMPTON ROADS REGIONAL SAFETY STUDY – 2013 UPDATE 1 PART I: CRASH TRENDS AND LOCATIONS Presented by: Keith