The big picture
TxDOT said 64% of eligible property owners returned ballots, with 92% voting in support of the wall’s construction. The barrier will be included in the upcoming University Segment of the I-35 Capital Express Central Project, which stretches from Hwy. 290 to Martin Luther King Jr. Boulevard and is expected to begin construction in mid-2026.
Sound barriers are typically installed when traffic sound levels reach 66 decibels or higher—roughly the volume of a normal conversation—or when future traffic is projected to double current noise levels, according to TxDOT documents. For comparison, a vacuum cleaner registers around 70 decibels, a whistle 80, and a blender 90.
According to Federal Highway Administration regulations, a noise wall should lower traffic sounds by about 5 decibels once it’s tall enough to block the direct view between the road and nearby homes. For every extra meter the wall is made taller after that, it can reduce noise by roughly another 1.5 decibels.
Some context
The work falls under the ongoing I-35 overhaul, which includes two new high-occupancy vehicle lanes in each direction, reconstructed east-west crossings and a new pedestrian bridge at Capital Plaza in this area. Construction is expected to wrap up in 2032.
