1. NCHRP 350 UPDATED

2. NCHRP 350 Historical Review Document Source Year Issued Number of Pages Test Vehicle & Weight HRB #482196214400 lb. car NCHRP #115 1971704000 to 5000 lb. cars. NCHRP #118 1972962000 & 4500 lb. cars NCHRP #153 1974192250 & 4500 lb. cars TRC #191 197827 *2250 & 4500 lb. cars NCHRP #230 198142*1800 & 4500 lb. cars NCHRP #350 1993132 *1800 lb. car & 4400 lb. Pickup *Large trucks also considered Current NCHRP Project 22-14(2) to Rewrite NCHRP 350

3. The current crash testing and evaluation standards were published in 1993 as NCHRP 350 (This was the first time that FHWA required that all newly installed safety hardware be capable of meeting the current evaluation criteria) “Recommended Procedures for the Safety Performance Evaluation of Highway Features.”

4. The Complete System End Treatment Longitudinal Barrier Transition Rigid Bridge Railing TEST LEVELS VEHICLE MASS IMPACT SPEED IMPACT ANGLE TL-1 2000kg (4400 lb) 50 km/hr (31mph) 25 deg TL-2 2000kg (4400 lb) 70 km/hr (43mph) 25 deg TL-3 2000kg (4400 lb) 100 km/hr (62mph) 25 deg TL-4 8000kg (17650 lb) 80 km/hr (50mph) 15 deg TL-5 & TL-6 36000kg (79400 lb) 80 km/hr (50mph) 15 deg

5. NCHRP 350 Terminal Tests Test Level 2 ~ 70 km/hr (43.5 mph) Test Level 3 ~ 100 km/hr (62 mph)

6. Time For a Change…..

7. NCHRP 350 Test Vehicles NCHRP 350 Test Vehicles For Barriers Test Vehicle MassLocation of Vehicle Center of Mass Small Car 1800 lb. (820 kg) 21.7 in. Pickup Truck 4400 lb. (2000 kg) 27.6 in. Single-Unit Van Truck (TL-4) 17,650 lb. (8000 kg) 66.9 in. Tractor Van Trailer (TL-5) 79,400 lb (36000 kg) 72.8 in. Tractor Tank Trailer (TL-6) 79,400 lb (36000 kg) 80.7 in.

8. Test Vehicles Have Changed

9. Process Started 1997 as NCHRP 22-14 (1) 22-14(2) Starting Date – August 2002 Expected Completion – February 2005

10. Identified Areas Where Revisions Could Have a Positive Impact on Safety. Identified Areas Where Revisions Could Have Improve Repeatability. Identified The Relevance of Each Change Relative to: Expected Additional Costs Expected Additional Benefits Resolve Inconsistencies. Improve International Harmonization.

11. NCHRP Project 22-14(2) Tasks --- PHASE 1 – DEVELOP WORK PLAN --- (1.) Conduct a brief review and reassessment of the 7 issues addressed in NCHRP Project 22-14(1). Topics that were addressed are:  Test vehicles and specifications  Impact conditions  Critical impact point  Efficacy of flair space model  Soil type/condition  Test documentation  Working width measurement

12. NCHRP Project 22-14(2) Tasks (2.) Review other relevant literature and ongoing research and conduct a survey to identify additional needs that were not addressed in the final report for Project 22-14(1). (3.) Identify potential revisions to the procedures.

13. NCHRP Project 22-14(2) Tasks (4.) Develop a test plan for assessing the crash test performance of existing roadside safety devices when subjected to the new procedures proposed in Task 3. The test plan shall consider, but is not limited to, crash testing and finite element analysis.

14. NCHRP Project 22-14(2) Tasks (5.) Submit an interim report documenting the findings from Tasks 1 through 4. The report, as a minimum, shall include the following: Summary and prioritization of information needed to update Report 350 Test plan developed in Task 4 Estimated costs and time Future research needs.

15. NCHRP Project 22-14(2) Tasks (6.) Meet in Washington, D.C., with the NCHRP panel to review the Task 5 interim report, including the test plan, approximately 1 month after its submittal. Submit a revised interim report reflecting the panel's review comments. STATUS REPORT ---- January 2004 : Above 6 Tasks Complete ----

16. NCHRP Project 22-14(2) Tasks --- PHASE 2 – IMPLEMENT WORK PLAN --- (7.) Execute the approved test plan. (8.) Submit for NCHRP review a preliminary draft final report documenting the entire research effort including an appendix, suitable for adoption and publication by AASHTO, containing the recommended procedures. (9.) Revise the preliminary report based on the project panel's recommendations.

17. NCHRP Project 22-14(2) Tasks (10.) Submit the revised report to an AASHTO task group for review. Summarize the comments from the task group review and make recommendations to the panel for revision of the report. Incorporate the approved recommendations into the procedures. (11.) Prepare and submit a final report documenting the entire research effort including an appendix containing the recommended procedures.

18. Specific Issues Being Addressed  Test Conditions

19. Specific Issues Being Addressed  Test Conditions  Test Vehicles

20. Specific Issues Being Addressed  Test Conditions  Test Vehicles  Critical Impact Point Selection

21. Specific Issues Being Addressed  Test Conditions  Test Vehicles  Critical Impact Point Selection  Soil Type / Conditions

22. Specific Issues Being Addressed  Test Conditions  Test Vehicles  Critical Impact Point Selection  Soil Type / Conditions  Efficacy of Flail Space Model

23. Specific Issues Being Addressed  Test Conditions  Test Vehicles  Critical Impact Point Selection  Soil Type / Conditions  Efficacy of Flail Space Model  Occupant Compartment Deform / Intrusion

24. Specific Issues Being Addressed  Test Conditions  Test Vehicles  Critical Impact Point Selection  Soil Type / Conditions  Efficacy of Flail Space Model  Occupant Compartment Deform / Intrusion  Windshield Damage

25. Specific Issues Being Addressed  Test Conditions  Test Vehicles  Critical Impact Point Selection  Soil Type / Conditions  Efficacy of Flail Space Model  Occupant Compartment Deform / Intrusion  Windshield Damage  In-Service Performance Evaluation

26. Specific Issues Being Addressed Test Conditions: Impact Speed: Now use 100km/hr (62.2 mph) TL-3. Recommend maintaining same impact speed and not changing to 110km/hr (68.4 mph). Consider “optional” impact speed of 110km/hr (68.4 mph).

27. Specific Issues Being Addressed Test Conditions: Impact Angles: (Barriers) Keep 25-deg for pickup truck. Currently use 20-deg for small car. Evaluate 20 vs. 25-deg for small car.

28. Specific Issues Being Addressed Test Conditions: Impact Angles: (Terminals & CC) Currently use 20-deg for pickup. Evaluate 20 vs. 25-deg for pickup.

29. Specific Issues Being Addressed Test Conditions: Side Impacts: Side impact testing may be added as an optional test.

30. Specific Issues Being Addressed Test Vehicles: Small Car Now use 1800# (820 kg) Small Car. An 1800# Small Car is no longer produced. Recommend using 2420# (1100 kg) Small Car.

31. Specific Issues Being Addressed Test Vehicles: Light Truck Now 4400# Pickup. Will use ¾ ton 5000# Pickup (std cab / 2-wheel drive) A 4400# (¾ ton Pickup Truck) is no longer produced. Over 21% of light trucks and 10% of all vehicles sold in 2001 weigh more than 4400#.

32. Specific Issues Being Addressed Test Vehicles: Intermediate Car Normally not used in testing. For barriers, it is believed if passes with small car and pickup truck, it will pass with this vehicle. May not always be true for staged attenuation systems.

33. Specific Issues Being Addressed Test Vehicles: Heavy Truck Now use 80,000# (36,000 kg) Truck. Issues are density of ballast and method to secure the load.

34. Specific Issues Being Addressed Critical Impact Point Selection The impact point varies depending on the device. The intent is to identify a potential failure impact point to create vehicle instability (i.e. wheel snag) or product failure.

35. Specific Issues Being Addressed Critical Impact Point Selection For terminals, currently use small car at a point between end of device and LON. Evaluate new CIP where device separates from redirective to gating.

36. Specific Issues Being Addressed Soil Type / Conditions Some devices perform better in weak soils (sign supports, W-Beam). Some devices perform better in strong soils (frangible sign supports). Soil types vary by test and by testing agency.

37. Specific Issues Being Addressed Efficacy of Flail Space Model For every crash, there are 3 impacts: 1. The vehicle with the hazard. 2. The body with the vehicle interior. 3. The internal organs with bones, chest and scull.

38. Specific Issues Being Addressed Efficacy of Flail Space Model Designed to estimate the speed at which an unbelted occupant would impact with the interior of a vehicle. Occupant Impact Velocity (OIV) and Ridedown Acceleration (RA) are measured.

39. Unrestrained Passenger Decelerations: –Under 9 m/sec preferred –12 m/sec max Occupant deceleration over a 10 millisecond period: –Should not exceed 15 G’s –20 G’s is allowable Specific Issues Being Addressed Efficacy of Flail Space Model

40. Specific Issues Being Addressed Occupant Compartment Deformation and/or Intrusion At what point does deformation into the passenger compartment become unacceptable? The location of the passenger compartment deformation is more critical in some areas.

42. Specific Issues Being Addressed Windshield Damage Windshield damage that currently defines test failure includes: 1. Any hole through the glass. 2. Any part of windshield becomes separate from the frame. 3. An area of cracking sufficient to obstruct the drivers view > 12” dia.

44. In-Service Evaluation Specific Issues Being Addressed

45. In-Service Evaluation Differences between field performance and crash test results can arise due to : Impact conditions different than test conditions such as non-tracking and side impacts. Site conditions different than test conditions such as a slope, curb, ditch. (before/during/after impact) Sensitivity to installation details as soil conditions or barrier flare.

46. In-Service Evaluation Purpose: Determine and document the manner in which the safety feature performs during a broad range of collision, environmental, operational and maintenance situations for typical site and traffic conditions. NCHRP 350

47. In-Service Evaluation Objectives: Are design goals achieved? Were installation problems incurred? Acquire wide range of collision data. Identify unforeseen problems or road modifications. Examine influence of severe climate or environmental conditions. Examine disruption of normal traffic patterns. Obtain information on maintenance.

48. In-Service Evaluation Proposed Approach: 3-Tiered System: Level I – Computerized data base. Level II – Supplemental field data collected. Level III – More detailed research such as accident reconstruction.

49. In-Service Evaluation Characteristics Example: 2-year minimum trial period. Sufficient length of barrier or number of devices to obtain data. Installations frequently examined. Evaluated on a before/after basis. Accident reporting technique established. Maintenance forces perform field evaluations. In-service report to be prepared.

50. CASE Reported Not Reported Repaired Not Repaired 1XX Types of Accidents:

51. CASE Reported Not Reported Repaired Not Repaired 1XX 2XX Types of Accidents:

52. CASE Reported Not Reported Repaired Not Repaired 1XX 2XX 3XX Types of Accidents:

53. CASE Reported Not Reported Repaired Not Repaired 1XX 2XX 3XX 4XX Types of Accidents:

54. Specific Issues Being Addressed Full Scale Crash Test Program Total of 12 tests proposed. Two tests with 4-wheel drive vehicle. Results used to estimate expected cost associated with implementing proposed test vehicles and test conditions.

55. Specific Issues Being Addressed Full Scale Crash Test Program (Early Priorities ASAP all at 25-deg. The results will determine the direction of future decisions.)  Standard W-Beam (steel post with wood block) with new pickup truck.  If above fails, Midwest Guardrail System with new pickup truck.  Permanent concrete SS small car.  Temporary concrete SS pickup.

56. MGS M idwest G uardrail S ystem W-Beam Barrier

57. What does the barrier need to do? Contain and redirect the barrier Perform to anticipated deflections

58. Sometimes You Just Get Lucky…

59. AASHTO Roadside Design Guide (updated 2002) Where does the barrier need to be placed?

60. Test Levels for Barriers NCHRP 350 Test Level For Barriers Largest Vehicle Mass Large Vehicle Impact Speed Impact Angle for Barriers TL-1 4400 lb. (2000 kg) 31 mph (50 km/h) 25 deg. TL-2 4400 lb (2000 kg) 43 mph (70 km/h) 25 deg. TL-3 4400 lb. (2000 kg) 62 mph (100 km/h) 25 deg. TL-4 17,650 lb (8000 kg) 50 mph (80 km/h) 15 deg TL-5 & TL-6 79,400 lb (36000 kg) 50 mph (80 km/h) 15 deg.

61. MGS M idwest G uardrail S ystem Introduction MGS research began in 2000 (non-proprietary) - 31” top rail height - reduced post embedment - 12” blockout depth - midspan rail splice Use of strong-post W-beam guardrails. Early W-beam systems designed for full-size sedans / small cars. Differing levels of safety performance for 27” high W-beam rails. Metrication led to 27-3/4” guardrail height – most systems had acceptable performance. Potential exists to improve barrier’s performance.

62. MGS Midwest Guardrail System

63. Background and Design Considerations Weaknesses of current W-beam design  Light truck rollover rates and high CG vehicles  Installation height sensitivity  Rail ruptures  Vehicle Override

64. 1,963 kg / 95.3 km/hr / 24.0 deg 686 mm (27 in.) Height Vehicle Rollover (Failure) Dynamic Deflection = 28.1 in.

65. 1,979 kg / 103.2 km/hr / 24.5 deg 706 mm (27.8 in.) Height Rail Rupture & Vehicle Penetration (Failure) Dynamic Deflection = NA

66. 2,034 kg / 99.8 km/hr / 27.7 deg 706 mm (27.8 in.) Height Vehicle Override & Redirection (Failure) Dynamic Deflection = 42.7 in.

67. Current and MGS W-Beam Comparison

68. Blockout Change From 8” to 12” Rail Post Blockout

69. Rail height will be changed to 31”

70. Rail Splices Mid-span Between Posts Rail Splices 12’-6” Rail Section

71. MGS Midwest Guardrail System (6’-3”) (40.12”) (31.89”) (12”) (31”) (24.89”)

72. 887 kg / 102.9 km/hr / 20.0 deg 813 mm (32 in.) Height Vehicle Redirected (Pass) Dynamic Deflection = 17.4 in.

73. 1,986 kg / 98.1 km/hr / 25.6 deg 787 mm (31 in.) Height Vehicle Redirected (Pass) Dynamic Deflection = 43.1 in.

74. Applications Along roadside with 6’-3” post spacing Positioning near hazards with limited space 1/4 (18 ¾”) or 1/2 (37 ½”) post spacing Placement over or near curbs 6” curb placed 6” in front of barrier MGS Midwest Guardrail System

77. The Terminal is Almost Completed

79. The “TF-13” Hardware Guide Published 1995

80. What About Inventories? Will They Change? Some Will Some Will Not

81. Midwest States Pooled Fund Program