To build the South Frontage Road extension or not to build it is not the key question about why it still exists only on paper.

Rather, it’s a matter of how much the cost has risen to build a mile of roadway, which drives everything when it comes to any road construction or improvement plan. The economic reality of rounding up millions of dollars to build overpasses, re-surface roads and reconstruct turn lanes is often at odds with the sausage-making process that is crafting budgets and writing law codes.

The bottom line is that the overpass must be built — no matter how long it has to compete for space on the state’s to-do list of highway work. It will make it much easier for vehicles to shop and dine on the city’s eastern flank and closes an illogical gap in local traffic flow that’s existed for far too long.

An overpass to take vehicles over the railroad tracks down in the gully between where South Frontage Road ends and the Outlets of Vicksburg has been the subject of talk for more than a decade. In 2005, intense lobbying over several years by mall officials when they joined city and county elected officials on their annual jaunt to Washington, D.C. secured the first $2.5 million for the project. Since then, the federal spigot has closed for a lot of small-scale local road and bridge projects of this ilk. You can thank the infamous “Bridge to Nowhere” for that. Thanks, Alaska.

To close a $17 million gap in funding for South Frontage and other unfunded road projects in Mississippi, state senators put language in the transportation budget to compel the Department of Transportation to put some money into it. The amount they chose was arbitrary, $4 million, likely a product of the murky process of budgeting. State Sen. Briggs Hopson and MDOT Central District Commissioner Dick Hall seemed to convey opposing emotions while agreeing the project is worthy of completion.

“It’s not ideal, but better than not completing it,” Hopson said, adding he hoped that the agency would use funds on hand to spur construction.

Hall, a Vicksburg native who represented Madison in the Legislature for 24 years before being appointed to the commission in 1999, said the earmark thrown into last week’s budget negotiations avoids the real issue with highway funding in the state.

“You can’t build it for $4 million,” Hall said in part, adding lawmakers need to pass a comprehensive highway bill and raise the gasoline tax to pay for it. “It’s certainly a nice gesture by Sen. Hopson to put it in there. But, you have to have the whole package. It makes no sense to just build a little piece over here and a little piece over there.”

Drawings at public hearings at the Vicksburg Convention Center a few years ago about the overpass and for a larger renovation of Interstate 20 in Vicksburg show an overpass that will take vehicles across the tracks. That’s a clearer driving path than stopping, contemplating a dangerous left turn against a tricky sight line down Old Highway 27, then being sure to avoid the interstate exit instead of the veer-right exit for East Clay to reach the other side of town. Drivers coming from Old 27 would be looped to overpass via a ramp to be built near the former site of Watkins Nursery, which sold its property to the state to speed up the project.

Hall and Hopson are both right. The politicians who control the purse strings in Jackson can’t let this project wither, nor can they be cynical about doing it in pieces. Interstates nationwide have a lonely support beam here and a piece of rebar there while money comes in; it’s not uncommon.

Stop piddling and build it.