4.2.1 Wall Types
4.2.1.1 Sound Walls
Sound walls are typically vertical masonry or precast stacked concrete panels between steel columns, with aesthetic treatments for color and texture (depending on location). Suburban, Urban, and Urban Core roadway contexts are best suited for this solution.
Sound walls are the most used form of noise abatement and are the only form of noise abatement required for consideration on Federal or Federal-aid projects in accordance with
23 CFR §772.13
. Sound walls are solid obstructions built between the highway and the receivers along the highway. Effective sound walls can reduce noise levels by 10 decibels, cutting the loudness of traffic noise in half.The advantages of sound walls are:
- Noise reduction between 5 -10dB(A), reducing traffic noise by as much as one-half; and
- Aesthetic treatment of walls provides area context and continuity.
The possible disadvantages are:
- Noise ‘bleed through’ where multiple driveways/medians may occur; and
- Increased construction costs.
4.2.1.2 Mechanically Stabilized Earth Walls
MSE walls make up the majority of TXDOT walls and provide an incredible palette for different textures, patterns, and colors within the roadway landscape.
4.2.1.3 Concrete Block Walls
These comprise a smaller portion of TxDOT walls. Concrete block walls are especially suited to areas where tighter curves may be needed, or where tiers of walls might be appropriate (shown in
).
Figure 4-10: Concrete Block Walls
4.2.1.4 Decorative Walls
These may be smaller accent walls used as visual transitions and landscape strategies, as described in
.