Status of the Roadside Design Guide Update

1
Status of the Roadside Design Guide Update
Keith A. Cota, New Hampshire Department of
Transportation

• AASHTO Subcommittee on Design July 19-23 2009
  Indianapolis, Indiana

2
Roadside Design Guide
3
Presentation Overview

• Update Objectives
• Research Studies
• Schedule for Completion

4
Update Objectives

• Statistics Updated
• Incorporated Latest Research
• Resolved Conflicts related to Clear Zone (NCHRP
  20-7, Task 171) within AASHTO Documents
• Clear zone
• Clear recovery area
• Horizontal clearance
• Lateral offset

5
Update Objectives

• Minimum Lateral Offset
• vs.
• Clear Zone

6
Update Objectives

• Reduced listing of hardware by referencing
  AASHTO-AGC-ARTBA Task Force 13 Report, A Guide
  To Standardized Highway Barrier Hardware
• http//aashtotf13.org

7
Update Objectives

• Referenced Acceptance Letters from FHWAs Office
  of Safety
• http//safety.fhwa.dot.gov/roadway_dept/
• road_hardware/index.htm
• Added Reference for Updated Crash Test Criteria
  Under MASH and FHWA/AASHTO Implementation Plan

8
Update Objectives

• New chapter on Low Volume Roads, including
  guidance on
• Clear zone
• Drainage placement
• Slope and ditch cross-sections
• Barriers (TL-2)
• Sign supports
• Utility pole placement
• etc.

9
Update Objectives

• Updated chapter for Urban Areas, including
  guidance on
• clear zone
• lateral offset (4-6 ft)
• landscaping (including median applications)
• sidewalk placement
• slope and ditch cross-sections
• sign supports
• utility poles placement
• traffic signals
• mailbox locations
• etc.

10
Urban Chapter Objectives

• Urban rights-of-way are often extremely
  restricted, limiting the applicability of
  clear-zone practice even in suburban-to-urban
  transitions.

11
Urban Chapter Landscape Buffer (Planting Strip)
Configuration
12
Update Objectives

• RSAP (Roadside Safety Analysis Program)
• Update will maintain current RSAP program
• Intent to supplement at time of completion of
  NCHRP 22-27, RSAP Update, currently under
  contract
• Anticipated completion 2010 or sooner?

13
Update Objectives

• Technical Assistance through NCHRP 20-7, Task
  240, Update of AASHTO Roadside Design Guide
• Contract with King Mak
• Provide technical assistance, research overview,
  and chapter consistency review

14
Research Studies

• NCHRP Project 22-17 Recommended Guidelines for
  Curbs and Curb-Barrier Combinations
• NCHRP 22-19 Aesthetic Concrete Barrier and
  Bridge Rail Designs
• NCHRP 16-04 Design Guidelines for Safe and
  Aesthetic Roadside Treatments in Urban Areas
• NCHRP 22-18 Crashworthy Work Zone Traffic
  Control Devices
• NCHRP 20-7 (196) Development of a Guide to
  Crashworthy Bridge Rail Systems
• NCHRP 16-04 Median Intersection Design for Rural
  High-Speed Divided Highways

15
Research Studies

• NCHRP 17-13 Strategic Plan for Improving
  Roadside Safety
• NCHRP 20-7 (171) Guidelines for the Selection of
  Cable Barrier Systems
• FHWA Memoranda on
• Guidelines for the Selection of W-Beam Barrier
  Terminal
• High Tension Cable on Slopes
• Design Considerations for Large Trucks
• Midwest Pooled-Fund States Study Development
  of Guardrail Treatments at Intersecting Roadways

16
Schedule

• Schedule for Adoption
• Final chapter reviews and Technical Committee
  balloting at September 2009 meeting in Delaware
• Ballot to SCOD in Fall 2009
• TCRS to address SCOD ballot comments, Sept 2010
  (or sooner)
• Ballot to SCOH in Fall 2010 (or sooner)

17
AASHTO Subcommittee on DesignIndianapolis,
Indiana July 19-23, 2009

• AASHTO Manual for Assessing Safety Hardware
  (MASH)
• Technical Committee on Roadside Safety

17
18
Background

• 1962 HRCS Circular 482 one-page document,
  specified vehicle mass, impact speed, and
  approach angle for crash tests
• 1973 NCHRP Report 153 16-page document, based
  on technical input from 70 individuals and
  agencies and a special ad-hoc panel
• 1978 TR Circular 191 addressed minor issues
• 1980 NCHRP Report 230 36-page document,
  brought procedures up to date with available
  technology and practices, updated the evaluation
  criteria
• 1993 NCHRP Report 350 Comprehensive update of
  230
• 2009 Manual for Assessing Safety Hardware (MASH)

18
19
MASH Summary of Changes

• Test matrices and conditions
• Test installation
• Test vehicle specifications
• Evaluation criteria
• Test documentation
• In-service performance evaluation

19
20
Test Matrices and Conditions

• Small car impact angle (20 degree to 25 degree).
• Impact speed for single unit truck test (80 km/h
  50 mph to 90 km/h 56 mph).
• Impact angle for terminals and crash cushions (20
  degree to 25 degrees).
• Gating terminal/crash cushion (Reduce angle from
  15 degrees to 5 degrees).
• Mid-size car test (Add 1500A test vehicle for
  staged impact attenuation devices).

20
21
Test Matrices and Conditions

• Barrier Testing Heights (Establish max. for small
  vehicle and min. height for pickup test)
• Critical Impact Points (CIPs) for reverse
  direction impacts
• TMA optional tests to mandatory (Define max/min
  truck weight, control ballast shifting and
  vehicle braking)
• Variable message sign and arrow board trailers
  (Require same test criteria as TMAs)

21
22
Test Matrices and Conditions

• Support structures and work zone traffic control
  devices (Add light truck test in addition to the
  small vehicle testing criteria)
• Longitudinal channelizing barricades (Add new
  category and recommended test matrix)
• EDR data collection (Provide data on impact
  conditions and accelerations from vehicle)

22
23
Test Installation

• Soil Condition (soil type, gradation, compaction
  and density)
• Embedment of Posts (not necessary with reporting
  of soil conditions)
• Components (provide documentation of components
  used)
• Installation Lengths (document length of test
  installation)

23
24
Test Vehicles

• Test vehicles (change small vehicle and pickup)
• Single unit truck mass (from 18000 to 22000 )
• Light truck test vehicle (Min. c.g. height of 28
  inches)
• Vehicle age (six years older or less)
• Truck box attachment (limit detachment, reduce
  inconclusive testing results)
• Vehicle damage (document external vehicle crush
  damage using NASS procedures)
• Crushable nose characteristics (develop updated
  surrogate vehicle testing from 1981 Volkswagen
  Rabbit)
• TMA support vehicle (Report maximum weight of
  support vehicle)

24
25
25
26
Evaluation Criteria

• Occupant risk (Modify calculations for Occupancy
  Impact Velocity and Ridedown Acceleration with
  vehicle yawing)
• Windshield damage (Provides more quantitative
  criteria apply criteria to structural support
  devices the same for work zone devices)
• Occupant compartment damage (Set objective
  criteria)
• Marginal pass (Strictly pass or fail criteria
  results)
• Maximum roll angle (Roll and pitch angle at 75
  degrees)
• Exit conditions (Report lane intrusions and exit
  angle with exit box criteria)
• Vehicle rebound for crash cushions (reporting
  criteria)

26
27
In-Service Evaluation

• Encourage in-service evaluation to demonstrate
  satisfactory field performance.
• Pool resources (partnering) between State
  proprietary device manufacturers.
• Disseminate information through resource channels
  like National Technical Information Services
  (NTIS), FHWA regional resource centers, and State
  pooled fund consortiums.
• Consider the establishment of new national center
  on in-service evaluation.

27
28
Full Scale Crash TestsUnder NCHRP 22-14(02)

• Conducted several full-scale crash tests of
  existing hardware, including
• Strong Post W-Beam System
• Midwest Guardrail System
• New Jersey Shaped Concrete Barrier
• F-Shape temp. concrete barrier with 3-loop
  connection
• Iowa Transition
• Tangent Guardrail terminal
• New Jersey Shaped Concrete Barrier (32 inches),
  failed TL-4 under MASH

28
29
AASHTO/FHWA Joint Implementation Plan

• All highway safety hardware accepted using
  criteria contained in NCHRP 350 may remain in
  place and may continue to be manufactured and
  installed.
• Highway safety hardware accepted using NCHRP
  Report 350 criteria is not required to be
  retested or recertified using MASH criteria.

29
30
MASH Implementation

• If highway safety hardware that has been accepted
  by FHWA using criteria contained in NCHRP Report
  350 fails testing using MASH criteria, AASHTO and
  FHWA will jointly review the test results and
  determine a course of action.
• Upon adoption of MASH by AASHTO, any new highway
  safety hardware not previously evaluated shall
  utilize MASH for evaluation and testing.

30
31
MASH Implementation

• Any new or revised highway safety hardware under
  development at the time the MASH is adopted may
  continue to be tested using the criteria in NCHRP
  350.
• However, FHWA will not issue acceptance letters
  for new or revised highway safety hardware tested
  using NCHRP Report 350 criteria after January 1,
  2011.

31
32
MASH Implementation

• Agencies are encouraged to upgrade existing
  highway safety hardware that has not been
  accepted under NCHRP Report 350 or MASH
• during reconstruction projects,
• during 3R projects, or
• when the system is damaged beyond repair.

32
33
MASH Implementation

• Highway safety hardware not accepted under NCHRP
  Report 350 or MASH with no suitable alternatives
  available may remain in place and may continue to
  be installed.

33
34
Contact Information

• Keith A. Cota, Chairman
• AASHTO Technical Committee on Roadside Safety
• New Hampshire DOT
• Hazen Drive, PO Box 483
• Concord, NH 03302-0483
• Tel [phone]
• Email kcota_at_dot.state.nh.us

34