Alternate Power from Highway concrete dividers?

Source

Stand near a busy roadway and you'll be buffeted by gusts of wind as cars pass by. The majority of energy used in highway transportation goes to move huge volumes of air out of the way of our vehicles, not moving the vehicles themselves. So why not harness that energy and make it something useful?

The New Jersey Barrier

Still in the research phase, Oberholzer has evolved his concept to harvest more energy. While his original proposal suggested a single row of vertical-axis rotary turbines, he’s recently discovered that double-stacked Darius turbines will capture the wind from both directions more efficiently. With this refinement, each barrier now “packs much more generating power.”

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IMO this is avery promising alternate power idea, now what is the total cost of implementing this?

This is a nice idea, but by the looks of the drawing much of the concrete bulk of the barrier has been removed and replaced with wind turbines behind metal grilles. It makes me wonder if this "barrier" functions as a barrier anymore.

I'm not criticizing the idea of wind energy from passing cars (in fact it's pretty clever), I'm just wondering if the modified concrete barrier as shown can still do its primary job.