Commuters along a segment of I-45 in north Houston are noticing a smoother ride these days. Engineers with the Texas Department of Transportation say a three-layer resurfacing project is smoothing out bumps for drivers. They also say the new surface will help the road better withstand a high volume of truck traffic, and that means less repair work.

TxDOT Assistant Area Engineer Henry Quiroga says the one-mile strip of freeway carries about 290,000 vehicles a day in both directions.

“The existing roadway was exhibiting a lot of cracking, potholes, and it was requiring maintenance on a more regular basis than desired.”

Quiroga laid out small samples of asphalt on the hood of his truck to explain the three-layer process that transformed the bumpy roadway into a smooth, glasslike surface. First, crews milled out four inches of the existing road bed. They then put down a hot asphalt rubberized surface that’s designed to seal the road bed from water. On top of that layer goes a fine mix of asphalt.

“The rich bottom layer, or RBL, is intended to actually move and flex with the roadway. Since it is a concrete sub-surface it’s going to tend to crack, so this is intended to try to deter the cracking for as long as possible.”

The final layer is a coarse two-inch asphalt mixture. Quiroga says the layers are designed to work together to handle the heavy volume of traffic, especially trucks. The smoothness of the roadway is gauged throughout the process. One of the things they look at is bumps per mile.

“We offer an incentive and a disincentive to the contractor. If he achieves good to excellent ride quality, this contractor stands to make up to $15,000 bonus.”

The project costs $1.9 million and was completed in about two weeks. Quiroga says like any road surface, potholes and cracks will develop over time. But he says their intent is to lengthen the amount of time between repairs — and that will mean fewer detours for drivers.

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