PORT GIBSON (AP) — The Mississippi Department of Transportation is awaiting a study on Bayou Pierre as part of its preliminary study of four-laning U.S. 61 through Port Gibson.

Michael Arnemann, an assistant to Central District Transportation Commissioner Dick Hall, said MDOT has not seen the study but it is finished.

The review, conducted since 2010 by Michael Baker Jr. Inc., will determine whether a straight shot through the city would result in a net rise in the stream, which runs near the north end of town.

Preservationists are opposing the U.S. 61 plan, citing its effects on historic homes, churches and live oak trees that line the road, also called Church Street, in the center of town.

Port Gibson contains the last segment of U.S. 61 in Mississippi not widened into four lanes between Interstate 20 in Vicksburg and the Louisiana state line. North of the town, U.S. 61 is four-laned to Vicksburg and on to Redwood. South of town, U.S. 61 is four-laned around Fayette and Natchez and reaches the Louisiana line at Woodville

While part of the route through town is already four lanes, other areas are not and would be widened under MDOT’s plan.

Also, a busy stretch of the highway would be re-striped into five lanes.

Widening 61 is among the final items left over from the 1987 Four-Lane Highway Program, a multibillion-dollar effort to upgrade state highways.