Holiday traffic won't be affected by construction crews widening a stretch of U.S. 278 from four to six lanes, but median closures and reduced speeds at night are on the horizon.

Widening five miles of the highway from S.C. 170 to Simmonsville Road begins Tuesday and is expected to wrap up in November 2013.

Beginning the week of Dec. 5, portions of U.S. 278 near Rose Hill Way and Rose Hill Golf Course may require nighttime lane closures, according to APAC Southeast of Savannah. The company won the $23.6 million contract for the widening project from the S.C. Department of Transportation.

Work crews won't close lanes until Jan. 2 -- after the heavy holiday traffic subsides, DOT assistant resident engineer Jared Fralix said.

At other times, lane closures can only occur from 7 p.m. to 7 a.m. When lanes are closed, the speed limit will be reduced to 35 mph.

Through the end of this year, most of the work will be on the road's shoulders during the day, including installation of erosion controls and tree clearing. Crews from utility companies also will relocate cables and wires, Fralix said.

Median crossovers will be closed as the widening progresses. They won't reopen until the project is completed, and some will be closed permanently.

The median closures include:

At Hampton Parkway near the Okatie River bridge. The median cut will be replaced by a concrete wall between 3 and 5 feet tall.

In front of the Stokes Brown Toyota dealership.

At Indian Hill Baptist Church.

At Baylor Drive; permanently closed.

At the entrance to Westbury Park.

A partial closure at the entrance to Plantation Business Park. Drivers won't be able to make a left turn out of the development, but those coming from Hilton Head Island will be able to make a left turn in, Fralix said.

A median crossover serving parishioners and students at St. Gregory the Great Catholic Church will remain open. Plans to close the median and build a frontage road have been delayed because of lawsuit by Berkeley Hall, whose residents oppose the frontage road.

A median serving Island West also will remain open.

DOT officials will update property and business owners on what to expect as crews begin working in their area, Fralix said.

A mix of federal, state and local money is paying for the project. The county share comes from a 1 percent sales tax for transportation projects approved by voters in a 2006 referendum.

Follow reporter Allison Stice at twitter.com/BlufftonBlogIP.

US 278 widening causes safety concerns at St. Gregory, Oct. 28, 2011

US 278 gets green light from DOT despite concerns, Sept. 16, 2011