The document summarizes research conducted by the Midwest Roadside Safety Facility on innovations and improvements to roadside and median barriers. It describes the development of the Midwest Guardrail System (MGS) to improve performance over traditional W-beam guardrails for high center of gravity vehicles. The MGS was modified to be 31 inches tall and underwent full-scale crash testing. Additional research optimized the MGS for applications such as long spans over culverts, attachment to bridges and culverts, and use on slopes. Stiffened portable concrete barriers were also researched to minimize deflections without anchorage.

1. Innovations and Research in
Roadside and Median Barriers
Ronald K. Faller, Ph.D., P.E.
Assistant Director & Research Assistant Professor
Midwest Roadside Safety Facility (MwRSF)
Nebraska Transportation Center
University of Nebraska-Lincoln
Lincoln, Nebraska
2012 MINK Local Roads Conference
Stoney Creek Inn
St. Joseph, Missouri
September 26-27, 2012

2. Midwest Roadside Safety Facility
Introduction
• 1.3 million traffic deaths & 50 million injuries per
year around world – significant societal impact
• 34,000 traffic deaths & 2.2 million injuries in 2009
in U.S. (NHTSA)
• ⅓ of fatal crashes w/ fixed objects
• Barrier innovations & ongoing research
 Midwest Guardrail System (MGS)
 long-span over culverts, low-cost bridge rail, side-mounted
attachment to culverts, MSE wall applications, non-blocked steel
post, rectangular wood post, minimum length
 Stiffened Portable Concrete Barriers (PCBs)
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3. Midwest Roadside Safety Facility
Midwest Guardrail System (MGS)
• Sponsored by Midwest States Pooled Fund
Program
• 50+yrs use strong-post W-beam guardrails
• Early W-beam systems designed for full-size
sedans & small cars
• Varied performance for 27” W-beam guardrail
• Metrication to 27¾” w/ many acceptable variations
• Improve performance for high c.g. vehicles
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4. Test No. 4798-7
1,963 kg/95.3 km/hr/24.0 deg
686 mm (27 in.) Height
Vehicle Rollover (Failure)
Dynamic Deflection = 28.1 in.
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5. Test No. 471470-27 Midwest Roadside Safety Facility
2,075 kg/101.4 km/hr/26.1 deg
686 mm (27 in.) Height
Vehicle Rollover (Failure)
Dynamic Deflection = 35.8 in.
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6. Midwest Roadside Safety Facility
Test No. MIW-1
2,007 kg/99.8 km/hr/25.8 deg
686 mm (27 in.) Height
Vehicle Rollover (Failure)
Dynamic Deflection = 39.4 in.
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7. Midwest Roadside Safety Facility
Design Concerns
• W-beam guardrail
weaknesses
 light truck and high cg
vehicle rollovers
 installation height
sensitivity
 rail ruptures
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8. Midwest Roadside Safety Facility
Design Modifications for MGS
• 31 in. tall & 40-in. embedment depth
• 12-in. deep blockouts
• Rail splices at midspans
• 6-ft 3-in. post spacing w/ W6x9s
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9. Midwest Roadside Safety Facility
Test No. NPG-1
887 kg/102.9 km/hr/20.0 deg
813 mm (32 in.) Height
Vehicle Redirected (Pass)
Dynamic Deflection = 17.4 in.
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10. Midwest Roadside Safety Facility
Test No. NPG-4
1,986 kg/98.1 km/hr/25.6 deg
787 mm (31 in.) Height
Vehicle Redirected (Pass)
Dynamic Deflection = 43.1 in.
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11. Midwest Roadside Safety Facility
Summary and Conclusions
• 31” MGS improved TL-3 safety performance over
27” W-beam guardrail
 improved stability for light trucks
 greater construction tolerances
 reduced concerns for rail rupture
• R&D on special applications
 reduced post spacing, curbs, 8:1 approach slopes, 2:1
fill slopes, MSE walls w/ 3:1 slopes, spanning culverts,
attachment to bridges & culverts, w/ & w/o blockouts,
AGTs, post options, increased heights, end terminals,
minimum length
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12. Midwest Roadside Safety Facility
MGS Long-Span Guardrail
• Sponsored by Midwest States Pooled Fund
Program
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13. Long-Span Guardrail w/ MGS Midwest Roadside Safety Facility
- 25-ft unsupported length
- uses breakaway wood posts
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14. Midwest Roadside Safety Facility
Test No. LSC-2
• 2,261-kg Dodge Quad Cab
• 99.6 km/h - 24.9 degrees
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15. 15

16. Midwest Roadside Safety Facility
MGS Bridge Railing
• Sponsored by Midwest States Pooled Fund
Program
• Research Objectives
 TL-3 guidelines of MASH
 low-cost bridge rail for rural highways & county roads
 available for use on bridges, including longer than 25 ft
 minimize deck width
 easy post replacement
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17. Midwest Roadside Safety Facility
Base Configuration
• Half-post spacing (3 ft - 1½ in.)
• S3x5.7 posts w/o blockouts
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18. Midwest Roadside Safety Facility
Side-Mounted Bridge Deck Connection
• 4”x4”x⅜” tube w/ top plate & L bracket
• 1” dia. A325 hex bolt
• Special deck reinforcement
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19. Test No. MGSBR-1
5,174-lb Dodge QuadCab
61.9 mph & 24.9 degrees
D.D. = 49 in. 19

20. Midwest Roadside Safety Facility
Test No. MGSBR-1
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21. Midwest Roadside Safety Facility
Test No. MGSBR-1
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22. Test No. MGSBR-2
2,586-lb Kia Rio
62.5 mph & 24.9 degrees
D.D. = 28 in. 22

23. Midwest Roadside Safety Facility
Test No. MGSBR-2
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24. Midwest Roadside Safety Facility
MGS Bridge Rail Adapted to Box Culverts
• Sponsored by Midwest States Pooled Fund
Program
• Research Objectives
 TL-3 guidelines of MASH
 low-cost guardrail for rural highways & county roads
 available for use on culverts, including longer than 25 ft
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25. Top-Mounted
One 1” Diam. Grade 2 Two ¾” Diam. Grade 2

26. Wrap-Around Side-Mounted
One 5/8” Diam. Grade 2 Two ¾” Diam. Grade 2

27. Midwest Roadside Safety Facility
Bogie Testing
• Lateral Impacts (strong-axis bending)
 20 mph & 25” load height
• Longitudinal Impacts (weak-axis bending & shear)
 20 mph & 12” load height
• No damage to culvert or attachment hardware

28. Midwest Roadside Safety Facility
Bogie Testing – Lateral Impacts
Side-Mounted Top-Mounted

29. Midwest Roadside Safety Facility
Bogie Testing – Longitudinal Impacts
Side-Mounted Top-Mounted

30. Midwest Roadside Safety Facility
Non-Blocked MGS on Wire-Faced MSE Walls
• Sponsored by Federal Lands Highway Division
(Western, Central, & Eastern) and Federal Highway
Administration
• Research Objectives
 TL-3 guidelines of MASH
 economical barrier to treat vertical drop-offs
 easily repaired
 consider modified MGS
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31. Welded Wire Wall - Sacramento River Road, NM
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32. Baseline Configuration
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33. Modified Configuration
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34. Midwest Roadside Safety Facility
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35. Midwest Roadside Safety Facility
Test Requirements and Criteria
• TL-3 of MASH
 1100C (2,425-lb) small car @ 62 mph & 25 degrees
 2270P (5,000-lb) pickup truck @ 62 mph & 25 degrees
3-10 3-11
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36. Midwest Roadside Safety Facility
Test No. MGSGW-1 (1100C)
61.0 mph & 25.3 deg
61.0 mph & 25.3 deg
2,596-lb Kia Rio
2,596-lb Kia Rio 36

37. Midwest Roadside Safety Facility
Barrier & Vehicle Damage (MGSGW-1)
Permanent Set – 20.1”
Dynamic Deflection – 27.4”
Working Width – 35.7”
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38. Midwest Roadside Safety Facility
Test No. MGSGW-2 (2270P)
65.3 mph & 25.1 deg
5,169-lb Dodge Ram 38

39. Test No. MGSGW-2 (2270P)
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40. Midwest Roadside Safety Facility
Barrier & Vehicle Damage (MGSGW-2)
Permanent Set – 26.2”
Dynamic Deflection – 35.7”
Working Width – 45.2”
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41. Minimum Lateral Offset
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42. Midwest Roadside Safety Facility
Conclusions & Recommendations
• Met TL-3 of MASH
• Economy w/ reduced structure width
• No MSE wall damage & barrier easily repaired
• Non-blocked MGS on level terrain?
• Use spacer blocks when possible
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43. Welded Wire Wall - Herber City, UT
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44. Midwest Roadside Safety Facility
Non-Blocked MGS on Level Terrain
• Sponsored by Midwest States Pooled Fund
Program
• Research Objectives
 TL-3 guidelines of MASH
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45. Midwest Roadside Safety Facility
MGS w/o Blockouts
Midspan
12” Backup Splice
Plate
6-ft W6x9
Steel Post
5/8” dia. x 1½” long
(splice bolts)

46. Test No. MGSNB-1
2270P Pickup Truck
62.7 mph & 24.7 deg
D.D. = 34 in.

47. Test No. MGSNB-2
1100C Small Car
63.0 mph & 25.5 deg
D.D. = 29 in.

48. Midwest Roadside Safety Facility
MGS w/ Rectangular SYP Posts
• Sponsored by Midwest States Pooled Fund
Program
• Research Objectives
 TL-3 guidelines of MASH
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49. Midwest Roadside Safety Facility
MGS with SYP Posts
12” Blockout
6”x8”x6’
SYP Post
5/8” x 22” Long
Bolt
31” Rail Height

50. Test No. MGSSYP-1
2270P Pickup Truck
62.2 mph & 24.9 deg
D.D. = 40 in.

51. Test No. MGSSYP-2
1100C Small Car
61.4 mph & 25 deg
D.D. = 22.2 in.

52. 2270P – 4 fractured posts
1100C – 2 fractured posts

53. Midwest Roadside Safety Facility
Blocked MGS: Wood vs. Steel Post
Pickup Truck Small Car
Evaluation Criteria MGS MGS Wood MGS MGS Wood
Steel Post Post Steel Post Post
OIV: Longitudinal (ft/s) 15.3 13.3 14.8 15.7
OIV: Lateral (ft/s) 15.6 14.7 17.1 20.9
ORA: Longitudinal (g’s) 8.2 8.1 16.1 13.0
ORA: Lateral (g’s) 6.9 8.5 8.4 9.3
Dynamic Deflection (in.) 43.9 40.0 28.6 22.2
IS (kip-ft) 122.3 115.5 55.0 56.4

54. Midwest Roadside Safety Facility
Minimum Effective Length of MGS
• Sponsored by Wisconsin Department of
Transportation
• Research Objectives
 minimum system length of MGS
 barrier deflections for various system lengths
 TL-3 guidelines of MASH
• 75-ft minimum length for full-scale crash testing
 historical length for crash testing – 175 ft
 prior recommendations for minimum length, excluding
bridge approach sections – 175 ft

55. Test No. MGSMIN-1
2270P Pickup Truck
62.9 mph & 25.0 deg
D.D. = 43 in.

56. Midwest Roadside Safety Facility
Lateral Stiffening of PCBs w/o Anchorage
• Sponsored by Wisconsin Department of
Transportation
• Research Objectives
 minimize barrier deflections without anchorage to bridge
decks
 utilize MwRSF’s 12.5-ft long F-shape PCB
 TL-3 guidelines of MASH

57. Free-Standing F-Shape PCB
MASH
Test No. 2214TB-2
2270P Pickup Truck
62.0 mph & 25.4 deg
D.D. ≈ 80 in.

58. Midwest Roadside Safety Facility
Modular Double Tube & Bent Plate
2 ft
5”x5”x3/16” steel tubes
10-gauge cover plate

59. MASH
Test No. RDTCB-1
2270P Pickup Truck
62 mph & 25 deg
D.D. ≈ 42 in.

62. Midwest Roadside Safety Facility
Deformed PCB System

63. Midwest Roadside Safety Facility
Deformed PCB System