Section 4: Concrete Railing
Anchor: #i1007421Traffic Railing Type T201
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This railing is a 27-inch high continuous concrete parapet. Its minimum height after maintenance overlays is 27 inches. NOTE: This railing is no longer used for new construction. It has been superseded for new construction by the T221 railing. |
The T201 railing is acceptable for TL-3 use. It has not been crash tested. However, TxDOT considers it similar in strength and geometry to the T203 railing, which has been successfully crash tested and approved for TL-3 use. See Figure 2-9, below.
Figure 2-9. Type T201 Railing
Anchor: #i1007446Combination Railing Type C201
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This railing is a 27-inch high continuous concrete parapet and a two-tube steel pipe rail mounted 42 inches above the ground. Its minimum height after maintenance overlays is 27 inches for the concrete parapet and 42 inches for the pipe rail. NOTE: This railing is no longer used for new construction. It has been superseded for new construction by the C221 railing. |
The C201 railing is acceptable only for TL-2 use (a design speed of 45 mph or less) because its pipe rail presents an occupant compartment intrusion threat to high speed vehicular traffic. See Figure 2-10, below.
Figure 2-10. Type C201 Railing (Left Rail)
Anchor: #i1007471Bicycle Railing Type B201
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This railing is 63 inches high with a 27-inch high concrete parapet supporting a chain link fence. Its 2-inch diameter standard pipe posts are spaced a maximum of 8 ft. apart. Its minimum height after maintenance overlays has not yet been established. NOTE: This railing is no longer used for new construction. It has been superseded for new construction by the B221 railing. |
The B201 railing is designed for bicycle and pedestrian loads only. It has not been crash tested and is not intended for exposure to vehicular traffic.
Anchor: #i1007485Traffic Railing Type T203
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This railing is 27 inches high with a continuous concrete top beam 14 inches high by 13.5 inches wide on 13-inch high concrete posts that are 5 ft. long and spaced a maximum of 10 ft. apart. Its minimum height after maintenance overlays is 27 inches. This railing is not recommended for direct connectors or flyovers. |
The T203 railing was successfully crash tested in 1998 and approved for TL-3 use. See Figure 2-11, below.
Figure 2-11. Type T203 Railing
Anchor: #i1007505Combination Railing Type C203
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This railing is identical to the type T203 railing but with a two-tube steel pipe rail mounted at 42 inches. Its total minimum height after maintenance overlays is 27 inches for the concrete rail and 42 inches for the pipe rail. |
The C203 railing is acceptable for only TL-2 use (a design speed of 45 mph or less) because its pipe rail presents an occupant compartment intrusion threat to high speed vehicular traffic. The C203 is usually mounted on a raised sidewalk attached to a bridge deck.
Anchor: #i1007514Traffic Railing Type T221
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This railing is a 32-inch high continuous parapet. Its parapet is taller and thicker than that of the T201 railing from which its design is derived allowing optional use of welded wire reinforcement. |
TxDOT considers this railing equal in strength to railings of like geometry that have been crash tested and approved for TL-3 use.
Anchor: #i1007523Combination Railing Type C221
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This railing is a 32-inch high continuous parapet with a single pipe rail mounted 42 inches above the roadway surface. It features a bolt anchorage system for the steel rail posts that may be drilled and epoxy-anchored allowing slip-forming of the concrete parapet. Its parapet is taller and thicker than that of the C201 rail, from which its design is derived, allowing for optional use of welded wire reinforcement. |
The C221 railing is acceptable for only TL-2 use (a design speed of 45 mph or less) because the pipe rail presents an occupant compartment intrusion threat to high speed vehicular traffic.
Anchor: #i1007532Bicycle Railing Type B221
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This rail is 68 inches high with a 32-inch high concrete parapet supporting a chain link fence. Its parapet is taller and thicker than that of the B201 rail from which its design is derived. |
The B221 railing is designed for bicycle and pedestrian loads only. It has not been crash tested and is not intended for exposure to vehicular traffic.
Anchor: #i1007541Traffic Railing Type T411
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This railing is a 32-inch high continuous concrete railing that has 6-inch wide windows spaced every 18 inches, center to center. Its minimum height after maintenance overlays has not yet been established. |
The T411 railing was crash tested in 1989 with a 4,500-lb. large car at 60 mph and at an angle of impact of 25 degrees. Later tests with a 4,409-lb. pickup truck at 60 mph and at an angle of impact of 25 degrees did not pass due to unacceptable occupant compartment intrusion. Therefore, this railing is not to be used in high-speed areas.
This railing is acceptable for TL-2 use (a design speed of 45 mph or less). See Figure 2-12, below.
Figure 2-12. Type T411 Railing
Anchor: #i1007566Combination Railing Type C411
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This railing is a 42-inch high continuous concrete railing that has 6-inch wide windows spaced every 18 inches, center to center. Its minimum height after maintenance overlays is 42 inches. |
Like the T411 railing type, this rail is acceptable for only TL-2 use (a design speed of 45 mph or less). See Figure 2-13, below.
Figure 2-13. Type C411 Railing
Anchor: #i1007586Traffic Railing Type T501
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This railing is a 32-inch high concrete safety-shaped parapet. Its minimum height after maintenance overlays is 29 inches. |
This rail has been approved for TL-4 use after evaluation of results from successful crash testing based on criteria that predate NCHRP Report 350. See Figure 2-14, below.
Figure 2-14. Type T501 Railing
Anchor: #i1007605Traffic Railing Type T501SW
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This railing is a T501 concrete railing with a 7 ½-inch thick vertical wall attached to the top of the T501 railing. The total railing height is 8 feet; however, a 6-foot version is available. This railing is designed for use on bridges and on pavement. The minimum height of the lower safety-shaped parapet after maintenance overlays is 29 inches. NOTE: No standard drawings are available for this railing. Working drawings in heights up to 10 ft. are available from the Bridge Division. |
The T501SW railing was successfully crash tested in 2000 and approved for TL-4 use. See Figure 2-15, below.
Figure 2-15. Type T501SW Railing
Anchor: #i1007630Combination Railing Type C501
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This railing is a 32-inch high concrete safety-shaped parapet that has a single steel pipe rail mounted 10 inches above the concrete. The minimum height after maintenance overlays is 42 inches. |
The C501 railing is acceptable for only TL-2 use (a design speed of 45 mph or less) because its pipe rail presents an occupant compartment intrusion threat to high speed vehicular traffic. See Figure 2-16, below.
Figure 2-16. Type C501 Railing (Right Rail)
Anchor: #i1007650Traffic Railing Type T502
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This railing is a 32-inch high concrete safety-shaped parapet with multiple drain slots. Its minimum height after maintenance overlays is 29 inches. |
The T502 railing is approved for TL-4 use.
Anchor: #i1007659Combination Railing Type C502
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This railing is a 32-inch high concrete safety-shaped parapet that has a single steel pipe rail mounted 10 inches above the concrete and that has multiple drain slots. The minimum height after maintenance overlays is 42 inches. |
The C502 railing is acceptable for only TL-2 use (a design speed of 45 mph or less).
Anchor: #i1007668Traffic Railing Type T503
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This railing is a 32-inch precast concrete safety-shaped parapet bolted to the slab with bolts spaced 4.5 ft. apart. Its minimum height after maintenance overlays is 29 inches. |
The T503 railing is acceptable for TL-4 use because TxDOT considers the T503 railing equal in strength and performance to the T501 railing, which has been approved for TL-4 use. Permanent installation of the T503 railing on a deck thinner than 8 in. is not recommended.
Anchor: #i1007677Traffic Railing Type T504
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This railing is a 32-inch high precast concrete safety-shaped parapet bolted directly to a 5-in. minimum slab on prestressed box beam and slab beam structures and double-T beams with bolts spaced about 4.5 ft. apart, center to center. Its minimum height after maintenance overlays is 29 inches. |
The T504 railing is acceptable for TL-4 use because TxDOT considers the T504 railing equal in strength and performance to the T501 railing, which has been approved for TL-4 use.
Anchor: #i1007686Traffic Railing Type SSTR
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This railing is 36 inches high with a concrete parapet that has a single front slope. Its minimum height after maintenance overlays is 32 inches. |
This railing was crash tested as a median barrier in 1990 with a 4,409-lb. pickup truck at 62 mph and at an angle of 25 degrees. This railing was approved for TL-3 use after evaluation of results from the 1990 crash testing. See Figure 2-17, below.
Figure 2-17. Type SSTR Railing
Anchor: #i1007706Traffic Railing Type TT
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This railing is 90 inches high with a 48-inch high safety-shaped parapet and a 21-inch high concrete beam mounted on 21-inch high concrete posts. Its minimum height after maintenance overlays has not yet been established. |
This railing has had only one use in Texas. It was crash tested in 1983 with an 80,000-lb. tank truck at 50 mph and at an angle of impact of 15 degrees. This railing was approved for TL-6 use after evaluation of results from the 1983 crash testing. See Figure 2-18, below.
NOTE: This railing is intended to protect highly vulnerable sites beneath a bridge. Additional bridge girders must be placed close to the edge of the bridge deck to support the weight and impact requirements of this rail.
Figure 2-18. Type TT Railing