Sound barrier muffles traffic noise on U.S. 17

Rene Vasquez guides a track hoe lifting a form of blocks as workers construct a sound barrier wall Thursday along Johnnie Dodds Boulevard in Mount Pleasant. The wall will be made of more than 86,000 blocks.

MOUNT PLEASANT — Stand outside of Alan Schmitt's home in Snee Farm and you can hear the cars on U.S. Highway 17 whizzing by. Inside, it's a different story.

It's much quieter even though traffic still stacks up a stone's throw from the rear of the house. The difference? A nearly completed $743,000 half-mile long sound barrier wall on U.S. 17 South. It's the first in town and a relatively new thing for the Charleston area.

'It's down to a quiet hum instead of a loud rush. I definitely notice a difference,' Schmitt said.

In January, the town began clearing land for the 3,000-foot-long, 10-foot-tall wall to separate the highway and the subdivision. The barrier is part of a $14 million project to widen 2.5 miles of the highway from four lanes to six from the Isle of Palms connector to S.C. Highway 41.

And it's also part of a much larger plan to create a six-lane road from the Arthur Ravenel Jr. Bridge to Darrell Creek Trail. The road will be widened toward the existing grass median that now separates northbound and southbound lanes.

Critics have said the wall is ugly and reflects poorly on the landscape around it. However, salesman Wade Wiggins at Lord & Evans Paints said the wall has eliminated an eyesore across from the store. 'It looks better than a lot of the junk that was over there,' he said.

The town studied U.S. 17 noise as part of an environmental assessment of the highway widening project. Noise levels were measured at dozens of locations. The study found support for the noise-barrier wall among Snee Farm residents.

The wall will be completed in September and runs along U.S. 17 South from near Long Point Road to near the Beaumont development. The road there averaged 53,725 vehicles daily in 2008, which earned it a 'D' grade for level of service. The letter grade means there are minimal delays but that the speed and ability to maneuver are severely restricted by the increasing density of vehicles, according to an environmental assessment of the project released last summer.

The study estimates that without the town's planned road-widening project for U.S. 17, the level of service for the highway would drop to an 'F' by the year 2030, meaning significant delays and sluggish stop-and-go traffic.