LOW COST SAFETY IMPROVEMENTS .Right Angle *NCHRP 500, Objective Right Angle Crashes 17.1 F2 –...

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Transcript of LOW COST SAFETY IMPROVEMENTS .Right Angle *NCHRP 500, Objective Right Angle Crashes 17.1 F2 –...

  • LOW COST SAFETY IMPROVEMENTSIMPROVEMENTS

    1-1

  • Introduction

    Highway Traffic Fatalities Trend43,220

    40,00045,00050,000

    25 00030,00035,000

    15,00020,00025,000

    05,00010,000

    1-2

    01988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003

  • Introduction

    U.S. Highway System Fatality Rate has decreased or remained

    same (as Traffic is Increasing)B t 42 000 D th & 2 920 000 I j i But over 42,000 Deaths & 2,920,000 Injuries per Year

    Lane Departure and Intersection CrashesEngineering focus areas Engineering focus areas

    Rural crashes (70% of fatals)

    1-3

  • Introduction

    Rural Road Safety by The Numbers

    3.54 Fatality Rate is

    2.5 times that for

    22.5

    32.5 times that for Urban Roads.

    40 % of Travel

    0.51

    1.5 40 % of Travel and 60% of Fatalities

    0

    Loca

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    1-4

    Min

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  • Introduction

    S f t b lSafety an absoluteSafer- a relative term

    1-5

  • Is this road safe or unsafe?

    LightingAdvance Warning SignsSigns Delineators Chevrons Chevrons Shoulder Rumble Strip

    Which of these low cost measures are required (i e nominal requirement)?

    1-6

    (i.e., nominal requirement)?

  • Substantive and Nominal Safety

    Nominal Safety is examined in Nominal Safety is examined in reference to compliance with standards, warrants, guidelines andstandards, warrants, guidelines and sanctioned design procedures

    Substantive Safety is the actual crash frequency and severity forcrash frequency and severity for highways or roadways

    1-7

  • Nominal Safetyy

    Nominal Safety Advance Warning Sign + Advisory Speed Plaque

    1-8

    Speed Plaque

  • Nominal Safetyy1st Step

    Speed limit = 45 mph Traffic Volume = 2,000 Traffic Volume 2,000 - Expect 2 crashes per year at this traffic volume

    Nominal Safety Advance Warning Sign + Advisory

    1-9

    Speed Plaque

  • Nominal and Substantive Safetyy1st Step 2nd Step

    Nominal Safety Advance Warning Sign + Advisory

    Advance Warning Sign + Advisory Speed + Chevrons =

    1-10

    g g ySpeed Plaque

    ySafer = Substantive Safety

  • AASHTO Strategic Safety Plan GuidebooksGuidebooks

    1-11

  • Typical Benefit/Cost Ratios

    * From MN DOT TrafficDOT Traffic Safety Fundamentals Handbook

    1-12

    Handbook

  • LOW COST SAFETY IMPROVEMENTSIMPROVEMENTS

    The Tools RoadsideRoadside Hazards

    1-13

  • Roadside Hazards

    Scope of the Roadside Problemp

    About one in three of allthree of all highway fatalities is the result of a single vehicle run-off-the road Crash

    1-14

  • Roadside Hazards

    Drivers May Leave the Roadway As A y yResult Of:

    Driver Error

    Collision Avoidance

    Roadway Condition

    Vehicle Component FailureVehicle Component Failure

    1-15

  • Roadside Hazards

    Driver LimitationsPerceive 2 or more events per second Make 1 to 3 decisions per secondTake 30 to 120 actions per minuteCommit at least one error every 2 minutesAre Involved in a hazardous situation every 2

    hoursHave 1 or 2 near collisions per monthHave 1 or 2 near collisions per monthAverage 1 crash every 6 years

    1-16

  • Roadside Hazards

    Trees Utility Poles Light Poles Sign Posts Mail Boxes Mail Boxes Steep Ditches Edge Drop Offs Edge Drop Off s

    1-17

  • Countermeasures for Roadside Hazards:Hazards:

    1. Trees removal & restriction of species2 Utility Poles - relocation2. Utility Poles - relocation3. Sign Supports breakaway and shielding4. Mail Boxes crashworthy5. Single-Vehicle Run-Off-the-Road - Rumble g

    Strips and Rumble Stripes

    1-18

  • Countermeasures forRoadside Hazards:Hazards:

    6. Slopes and Ditches

    7. Rumble Strips

    8. Rumble Stripesp

    9. Safety Edge

    1-19

  • Countermeausures for Trees

    Proven

    CRF = 22%to 71%

    *NCHRP 500, Volume 3- Guide for Addressing Collisions

    1-20

    gwith Trees in Hazardous Locations

  • Countermeasures for Relocation of Utility PolesUtility Poles

    Relocate UtilityRelocate Utility Pole away from edge of pavement

    1-21

  • Reduction in Utility Pole Crashes for Pole Relocationfor Pole Relocation

    1-22

  • Crashworthy Sign Supports

    Small signSmall sign Supports less than 50 Sq Foot

    T 1 H lTwo 1 Holes in a 4 x 6 wood post

    1-23

    wood post

  • Countermeasures for Street Light PolesPoles

    Light Pole within 1 foot of back of curbNon-Breakaway steel light pole g p

    *NCHRP 500, Volume 6, Strategy 15.1 C1

    8 ft

    Strategy 15.1 C1 Improve Roadside Hardware (Light Poles and Sign Posts)

    1-24

    and Sign Posts)

  • Countermeasures for Mailboxes

    8 h d d8 hardened steel gas pipepipe

    *NCHRP 500, Volume 6, Strategy 15.1 B2

    1-25

    gyRemove/Relocate Objects in Hazardous Locations

  • Update/Replace Roadside HardwareHardware

    ReplaceReplace Antiquated Guardrail andGuardrail and Terminals

    NCHRP 500, Volume 6, Strategy 15.1 C1

    1-26

    gyImprove Roadside Hardware

  • Update/Replace Roadside HardwareHardware

    NCHRP 350 compliant endcompliant end terminal

    1-27

  • Countermeasures for Slopes

    Power pole in toe of ditchD OffDrop- Off

    Non-blrecoverable

    slope

    *NCHRP 500, Volume 6, Strategy 15.1 B1 Design

    1-28

    Strategy 15.1 B1 Design Safer Slopes and Ditches

  • Countermeasures for Slopes

    Traversable SlAfter Condition SlopeAfter Condition

    Ditch Filled In

    NCHRP 500, Volume 6, Strategy 15.1 B1 Design

    1-29

    Strategy 15.1 B1 Design Safer Slopes and Ditches

  • Countermeasures for Run-Off-the-Road CrashesRoad Crashes

    Rumble strips are intended to supplement pavement markingspavement markings Adds sound and vibration to the

    visual benefits of painted markings

    Provide a drowsy, inattentive, or distracted driver with a cleardistracted driver with a clear warning that the vehicle has left travel lane

    Provides some reaction time before the vehicle leaves the road

    1-30

    road

  • Countermeasures for Run-Off-the-Road Crashes Edgeline Rumble

    StripsCRF = 20 to 49% for 2 Lane Tried

    NCHRP 500, Volume 6 St t 15 1 A16, Strategy 15.1 A1 Install Shoulder Rumble Stripsp

    1-31

  • Countermeasures for Run-Off-the-Road Crashes Centerline

    Rumble Strips

    Two-Lane Hwy Undivided 4-Lane Hwy1-32

    Two-Lane Hwy Undivided 4 Lane Hwy

  • Rumble Stripes

    NCHRP 500, Volume 6, Strategy 15.1 A2 Install Edge line Profile marking

    1-33

    g

  • Rumble Stripes

    Rumble Stripes on MS 589

    Mississippi

    NCHRP 500, Volume 6 Strategy 15 1 A26, Strategy 15.1 A2 Install Edge line Profile Marking

    1-34

  • Rumble Stripes

    Michigan Michigan initiative with edge line Normal edge line painted over shoulder rumble

    Edgeline

    Rumble shoulder rumble strip Edgeline

    Comparison of painted edgeline in RainNCHRP 500, Volume 6, Strategy 15.1 A2 Install

    1-35

    Strategy 15.1 A2 Install Edge line Profile Marking

  • Rumble Stripes

    Michigan Michigan initiative with edge line Normal edge line painted over shoulder rumble

    Edgeline

    shoulder rumble strip.

    Michigan I-75Aft 1st Wi t

    1-36

    - After 1st Winter

  • Reducing Edge Drop Off Crashes

    Example of EdEdge Drop-Off Crash Normal Crash

    EdgelineCounty Road

    lrecently resurfaced Edge drop offEdge drop-off resulted in 3 Fatalities

    1-37

    Fatalities

  • Reducing Edge Drop-Off Crashes

    Normal Edgeline

    Edge Drop-off

    1-38

  • Reducing Edge Drop-Off Crashes

    Pavement Edge Rutting and Drop-Offs: Edge rutting occurs on all sections of roads Usually a small percentage of road lengthy p g g Caused by errant vehicles in conjunction

    with erosionwith erosion Common in curves and near turning

    movementsmovements Mailboxes

    1-39

  • Reducing Edge Drop-Off Crashes

    SafetyNormal

    Safety Edge

    EdgelineEdge

    NCHRP 500, Volume 6, Strategy 15.1 A8 Apply Shoulder

    1-40

    pp y S ou deTreatment

  • The Safety Edge

    Helps errant vehicles to maintain stability particularly on roadway re-entry

    Effective up to 5 inches of pavement depth

    Beneficial in reducing Tort Liability during t ti & ft j t l ticonstruction & after project completion

    NCHRP 500, Volume 6, Strategy 15.1 A8 Apply Shoulder

    1-41

    gy pp yTreatment

  • The Safety Edge

    Demonstration Project in Georgia

    Shoe Installed inInstalled in Screed

    1-42

  • The Safety Edge

    Demonstration Project in Georgia

    The Safety Edge

    1-43

    Edge

  • Countermeasures for Roadside HazardsHazards

    Delineate HazardsDelineate Hazards

    *NCHRP 500, SVolume 6, Strategy

    15.1 B3 Delineate Trees or Utility Poles ywith Markers or Retroreflective Tape

    1-44

  • LOW COST SAFETY IMPROVEMENTSIMPROVEMENTS

    The Tools Signing &

    Markings &Markings & Lighting

    1-45

  • Signing & Markings & Lightingg g g g g

    DiscussionDiscussion

    Signs: Markings:g Warning Signs Unexpected Hazards