TxDOT evaluates bridge rails for use on Texas bridges based on several criteria including, but not limited to: crash worthiness; the usefulness for new and retrofit bridge rails; the ease of installation; availability of the individual components; cost of the rail; long term durability; and required repairs after impact. For a bridge railing type to be considered for approval for use on Texas bridges it must meet one of the following crash worthiness determination:

Meeting the above crash worthiness criteria does not guarantee approval of the bridge rail for use on Texas bridges.

Use the greater of the posted speed or design speed at the bridge location to determine the test level required for the railing on the bridge.

All bridges with speeds above 45 mph must have railings that meet TL-3 criteria or greater. Bridges with speeds of 45 mph and below must have railings that meet TL-2 criteria or greater.

The AASHTO LRFD Bridge Design Specifications describes Test Level 4 as "taken to be generally acceptable for the majority of applications on high-speed highways, freeways, expressways, and Interstate highways with a mixture of trucks and heavy vehicles." Based

on this recommendation, bridge railings rated TL-4 as per MASH 2016 are required for new construction and for bridge railing upgrades of all bridges carrying the main lanes of Interstate highways and divided highways. Bridge railings rated TL-4 are recommended for other routes that carry a mixture of trucks and heavy vehicles.

Additional guidance on rail type selection can be found in Appendix A.

Bridge railing on any Texas bridge must connect with roadside metal beam guard fence if it is present. TxDOT provides railing transition details in the TxDOT Design Division Roadway Standards and transition connection details in the TxDOT Bridge Division Bridge Standards. Select the transition appropriate for the speed. Speeds of 50 mph and above require a TL-3 transition. Speeds of 45 mph and below can use a TL-2 or TL-3 transition.

All ends of bridge railings must be protected with the appropriate metal beam guard fence and end treatment, per the Roadway Design Manual, with the following exception.

Roadway classifications of urban and suburban, curbed sections, with speed of 45 mph and less may omit protection if both of these criteria are satisfied:

This exception does not supersede the need to protect steep side slopes, in accordance with the Roadway Design Manual. If the criteria are not met or steep side slopes are present, and metal beam guard fence cannot be installed, consideration must be made to extend the bridge railing around the corner of the intersecting street or driveway.

Protect the ends of bridge-class pipe and box culverts by providing, in order of preference, safety end treatments, metal beam guard fence, or bridge railing as described in the Drainage Facility Placement section of the regardless of horizontal clearance (clear zone). Exceptions to this can be obtained by approval of Design Exception or Design Waiver Request. Submit Design Exception and Design Waiver Requests to Bridge Division.

Exceptions to protecting the end of a bridge class culverts:

Bridge railing is frequently not an option with bridge-class pipe culverts. A pedestrian railing used alone is not acceptable for bridge-class culverts; traffic railing or combination railing must protect pedestrians and pedestrian railing from vehicular traffic on bridge-class culverts. For bridge-class culverts with raised sidewalks, use an approved combination railing.

Properly anchor bridge railings on box culverts using the details shown on the standard drawing and the details shown on the standard drawing for the selected bridge railing type.

For existing box culverts where bridge rail is required, anchor the railing properly using the details shown on the standard drawing for the selected bridge railing type and the details shown on the Rail Anchorage Curb Retrofit Guide drawing, which applies for fill heights of 2 ft. or less. If the drawing does not apply, the Bridge Division is available to provide project specific details for the addition of bridge railing.

Metal beam guard fence meets TL-3 requirements and can be provided as an option to bridge railing in the following ways:

Roadways elevated on retaining walls that are in-line with the edge of bridge slab or edge of traveled way require bridge railing, extended along the retaining wall until the drop-off terminates. The bridge railing and side slopes must be protected with the appropriate metal beam guard fence and end treatment, in accordance with the Roadway Design Manual.

Roadways elevated on retaining walls that are offset from the edge of bridge slab require one of the following railing options:

TxDOT does not recommend installation of precast concrete sound barriers mounted on top of concrete bridge railing for these reasons:

Sound walls may be placed behind a concrete traffic barrier, with a 2 ft. 10 in. minimum distance from face of traffic barrier to face of sound wall, taking into account posts or pillars in the wall that may project in front of the wall panels.

The Bridge Division has working drawings of a sound wall cast integrally on top of a single-slope concrete traffic railing. This railing with sound wall has been evaluated and approved for TL-5 (MASH 2016) use. Non-standard bridge slab details or custom foundations are required with this railing.

Bridge rail surface treatments, such as form liners may be used on the field side of the rail. The rail standard must be modified to increase the clear cover by the depth of reveals or amplitude of the pattern.

Stone or brick grouted veneers may not be used on top of the rail, the traffic face, or field side over grade separations or interchanges.

Treatments, such as form liners, on the traffic face of the bridge rail must be approved by Bridge Division.

Treatments must not have a component that could become an intrusion threat or snag any part of the vehicle.

Requests to place decorative fencing on bridge rails are frequently made to enhance bridge or project aesthetics. Unless the proposed fencing is proved crashworthy by full-scale crash testing, the following requirements must be met when a decorative fence is added to a bridge rail.