Construction on the Back Gate Interchange Project starts Monday, and even though work will be done during the day, drivers might not see traffic getting worse than it is.

Project leaders plan to build ways to avoid the center of the construction project, and plan to keep two northbound and southbound lanes open all the time.

Representatives met Wednesday to discuss the specifics of the three-year project that tens of thousands of drivers will see at U.S. 17 Bypass and S.C. 707 each day.

"Even if you travel it every day, you're going to come up on it one day and there's going to be a new traffic pattern, or there's going to be some new pavement, or there's going to be a traffic shift," said Mike Barbee, Horry County project manager for the S.C. Department of Transportation.

The project is divided into seven stages, with the first set to run from Monday through September. The goal is to build an overpass that will carry through traffic past that frequently jammed intersection, while leaving the area at ground level for people turning onto Farrow Parkway or S.C. 707. All construction is scheduled for completion in August 2014.

In the first stage, workers will install temporary and permanent drainage, construct temporary pavement in the median on the south end of the project and build the Temperance Drive connector.

Steve Gosnell, with Horry County Infrastructure and Regulation, explained that the Temperance Drive connector will extend from the end of the existing Frontage Road near Palmetto Pointe Boulevard across the entrance to the Oak Forest community and over to Farrow Parkway.

"We had to provide them additional access," Gosnell said about the Oak Forest residents.

The speed limit within the construction zone will be reduced from 55 mph to 45 mph. Daytime construction hours will run from 7 a.m. to 4:30 p.m., and drivers can get traffic updates by tuning to 1680 AM on their radios. Seventeen message boards will also surround the project area.

Barbee doesn't anticipate a lot of impact to U.S. 17 Bypass in the early stages of work.

"Once you get further along and you start to do work with the ramps and there's a need for temporary barriers, that's when the reduced speed limits will come into play," he said.

Phases of work

Construction on the two northbound on and off ramps begins in stage two, which runs from September until April 2012. At that point, northbound traffic will use the Temperance Drive connector to get to Farrow Parkway, while the rest of the traffic will continue using the existing lanes.

By stage three, running from April to October 2012, the northbound traffic shifts to the completed ramps, while southbound traffic moves to the existing northbound lanes. At this time, the two southbound on and off ramps will be constructed.

Southbound traffic shifts to these two ramps during stage four, which is set to run October 2012 to October 2013. During this stage, construction of the overpass begins.

Barbee said that throughout the construction, north and south turn lanes into The Market Common area will remain open.

Night and day

In the early stages, Barbee said all ramp work that can be done behind a concrete barrier and doesn't affect the flow of traffic will be done during daylight.

However, once it's time to start setting the overpass's beams, he anticipates most of the work shifting to the evening hours.

"Typically, these projects do involve a lot of night work as you get down to the bridge," he said.

Lane closures won't occur during the day, but Barbee said nighttime closings are a possibility, perhaps from midnight until 5 a.m.

"This, at some on and off times, will be a 24-hour, seven-day-a-week operation," he said.

Regarding night work, Barbee said it can be problematic because, even with all the flood lights that are used, there's still a visibility issue.

"It's impractical to build it all at night or during the day," he said.

Nighttime work on the project also led to an issue regarding asphalt and concrete batch plants.

The county has tried to decide if and how to allow plants that prepare concrete and asphalt to operate at night, allowing projects like the back gate overpass to occur with a minimum of public inconvenience.

Today, the Horry County Planning Commission is set to vote on a recommendation to amend the county's zoning ordinance, which includes allowing existing facilities to continue operating and limiting temporary batch plants to two years.

The amendment would then move on to the Horry County Council for a formal vote.

Gosnell said crews have several months of work to do before reaching a point where concrete is poured.

"Most of the concrete for the job is going to be for this bridge," he said.

Barbee said batch plants are left up to the contractor, and he didn't know what their plans were at this time. Balfour Beatty, a British firm with offices in Wilmington, N.C., will handle construction. The firm estimates the project will cost $75.7 million.

The county budgeted between $95 and $105 million for the project, with money coming from the 1-cent capital project sales tax passed in 2006.

Rick Tanferno, infrastructure and project manager for Balfour Beatty, said the construction will bring between 50 and 100 jobs.

Go around

There will be no specific detours through the construction area, other than the four ramps that will carry traffic around the space where the bridge is going to be built, Gosnell said.

With construction set to last for the three years, organizers advise drivers to avoid the intersection of U.S. 17 Bypass and Farrow Parkway if at all possible.

Alternates routes include U.S. 501 to U.S. 17 Business, over to S.C. 544 and on to S.C. 31.

"Yeah, it's a little bit longer, but you're going to sit in traffic for a little while (at the construction site)," Gosnell said. "The conditions are going to deteriorate from what they are today. How much and how long, I don't know. Usually it'll be bigger at the beginning and then tail off once everybody gets used to it."