Charleston County's road construction plans associated with the Boeing manufacturing facilities are expected to have large impacts on regional traffic, particularly between Interstate 526 and Ladson Road.

It's a more than $270 million construction plan that's expected to be completed by 2020, with some roads completed as early as 2017. So far, the county has only $80 million in funding for the plan, however.

All of the work planned falls in the city of North Charleston. Mayor Keith Summey has said the state needs to raise the tax on gasoline to fund such road plans.

"Nobody wants to pay more for a gallon of gas, but until somebody does, we're not going to have any money to build roads," he said following a recent presentation on the county's road plans.

The road construction work would come in three parts - the International Boulevard and Michaux Parkway connector roads around Charleston International Airport; a plan to turn South Aviation Avenue into a major road connecting to Palmetto Commerce Parkway, with a flyover at Ashley Phosphate Road; and plans for a partial interchange on Interstate 26, providing a new route to Palmetto Commerce Parkway, and to the planned Ingleside development and Bass Pro Shops store.

County officials and Rhett Reidenbach, of the engineering firm Davis & Floyd, gave an update on the plans to members of North Charleston City Council on Jan. 16. Here's where they stand:

Airport connector roads: Charleston County plans to schedule public meetings in February, August and December to explain details and get input. The target date to start construction is November 2015, with completion in the first half of 2017.

The roughly $42 million plan calls for a new major road from West Montague Avenue to Michaux Parkway and the airport, generally following a power line between the former Trailwood mobile home park - now owned by Boeing - and the Glyn Terrace and Northpointe neighborhoods.

A new route to the airport would separate airport traffic from Boeing-related traffic. The main Boeing facility is located along the current airport access road, International Boulevard.

South Aviation Avenue: The $180 million plan to turn what is now a minor airport access road into a major route between the Boeing facilities and Palmetto Commerce Parkway could take seven years, and could impact more than 140 property owners in Midland Park and areas nearby. The plan calls for running a new road along the east side of the Norfolk Southern rail line, roughly where Ward Avenue is located, continuing to a flyover at Ashley Phosphate Road, connecting to Palmetto Commerce Parkway.

The proposed road would create a link between Boeing's main facilities and its interiors plant, but would also create an alternative to parts of Interstate 26. The county estimates that 13 percent of traffic from I-26 and Dorchester Road would move to the new route, along with 20 percent of Rivers Avenue traffic.

Charleston County expects to schedule public meetings in June and October, and in June 2015, to provide details. Construction is not anticipated until mid-2017.

New I-26 interchange: This $50 million plan would create a new, partial interchange on the interstate between Ashley Phosphate Road and Highway 78, reducing traffic on both of those roads according to the county.

Charleston County is expected to hold public meetings in September and in June 2015, and hopes to start construction in November 2016. Current plans say the interchange could be finished at the end of 2018.

Reach David Slade at 937-5552