An Interstate 73 summit with North Carolina on Thursday and Friday is crucial to resolving when and if the neighboring state will build its three-mile remaining piece of the highway, South Carolina leaders say.

The summit on I-73 will be held in Myrtle Beach. North Carolina also wants to talk about other road projects, such as extending I-20 from Florence to Wilmington, N.C., and linking I-74 from its Brunswick County, N.C., end to the Carolina Bays Parkway in Horry County.

“This is an I-73 summit,” said Betty Mabry, director of the S.C. Department of Transportation. Congress has not designated an extension of I-20 or an I-74 spur into South Carolina, she said.

Lyndo Tippett, North Carolina’s secretary of transportation and Mabry’s counterpart, said he agrees I-73 is important to both states.

“Equally important to North Carolina are I-74 and the extension of I-20 to North Carolina,” he said in a written statement.

Interstate 73, planned to run from Sault Ste. Marie, Mich., to Myrtle Beach, would be the first Horry County interstate highway link. The Myrtle Beach area is the largest tourism destination in the country without an interstate highway connection.

Studies are under way, and preliminary suggested corridors for the stretch of I-73 between Myrtle Beach and I-95 will be presented at public meetings in early March.

The two Carolinas have continued to discuss, but not resolve, the road connection since I-73 was designated by Congress in 1991.

South Carolina leaders say North Carolina has resisted finishing the link because it does not want to encourage its residents to travel to South Carolina’s beaches. That also is why North Carolina insisted on building I-74, some say.

North Carolina has built parts of I-73 and I-74, which would split off I-73 near Rockingham, N.C., and turn east to the coast. South Carolina has just gotten the required preliminary studies under way for its I-73 route.

South Carolina has set aside for the time being the studies of the western half of the roughly 80-mile road until an accord is reached with North Carolina.

Mabry said the two states need to do a joint environmental study on the section where the two roads would come together, to meet federal requirements.

State Rep. Alan Clemmons, R-Horry, is president of the S.C. I-73 Association and said the discussion should focus on the I-73 connection with North Carolina.

“We want to know when they intend to build it, if they intend to build it, and what other projects are on their wish list,” he said.

An extension of I-74 southward into northern Horry County is a more likely possibility for agreement than the I-20 extension, Clemmons said.

The summit will be Friday at Embassy Suites at Kingston Plantation.

“We’re going to come with open ears and open minds,” said Brad Dean, president of the Myrtle Beach Area Chamber of Commerce.