Throughout the 2016 campaign and into the early stages of his presidency, Donald Trump vowed to make infrastructure improvements around the country.

The promise was all part of his brand of populism — spend more money domestically and less abroad. America first.

“We need members of both parties to join hands and work with us to pass a $1 trillion infrastructure plan to build new roads and bridges and airports and tunnels and highways and railways all across our great nation,” Trump pledged at a campaign rally in Melbourne, Florida, earlier this year.

Given Trump’s Russia investigation toxicity, it will be very tough for a $1 trillion infrastructure package to make it through Congress, at least in the near term. The most conservative members of the Republican caucus likely will not go along with it.

Trump would need a sizable proportion of the Democratic members of Congress to join pro-infrastructure-spending Republicans.

For the sake of argument, let’s assume eventually Trump and the GOP leadership can muster the necessary votes to get $1 trillion in infrastructure spending signed into law.

Let’s take a step further and say — with Sen. Richard Shelby in the Senate and an Alabama delegation in the House rising in seniority — some of this funding makes it to the Yellowhammer State to fund a laundry list of highway projects.

In 2016, a Washington, D.C.-based private nonprofit organization called TRIP compiled a wishlist of Alabama highway projects that it claimed would improve “growth and quality of life.” Among the Mobile-area projects were improvements to Interstate 10 across Mobile Bay, widening U.S. 98 and I-10 from Mobile to the Mississippi state line and more lanes in Baldwin County for I-10. There were others around the state — a freeway bypass in Montgomery, widening the perpetually clogged I-65 in Shelby County and improvements to Ross Clark Circle in Dothan.

All of those proposals are worthy of consideration. Over the last 30 years, Alabama’s metropolitan areas have grown, but the thoroughfares in those areas have been woefully unprepared for that growth.

Will highway projects like these spark new economic growth for Alabama? Not necessarily.

Consider Mississippi as a limited case study.

When you leave Alabama going into Mississippi on any of the major highways leaving Mobile — U.S. 98 headed toward Hattiesburg or U.S. 45 headed toward Meridian — the road magically widens from a treacherous, curvy Alabama two-lane road to a straight four-lane Mississippi highway — often with hardly a vehicle in sight.

The reasons for this disparity can be found in Washington, D.C. The Mississippi congressional delegation over the years has been very successful steering federal funds to its state. For a period, Republican Trent Lott was the majority leader of the Senate. Sen. Thad Cochran is the third-longest serving U.S. senator (a Republican in office since 1978), behind Sens. Patrick Leahy (D-Vermont) and Orrin Hatch (R-Utah).

In the years following the construction of the Tennessee-Tombigbee Waterway — a waterway that connects the Tennessee River to the Tombigbee River, empties into the Mobile River and exits into Mobile Bay — Mississippi started putting an emphasis on improving its highways.

You can crisscross the state of Mississippi without having to navigate a congested two-lane road for the most part. If you want to drive from Natchez to Corinth, Pascagoula to the Memphis suburbs, Jackson to Tupelo or Columbus to Greenville, the trip can be multi-lane all the way.

As many well know, that is not the case in Alabama. The quickest way from Mobile to Dothan consists mostly of driving through the Florida Panhandle. Trying to get from Mobile to Tuscaloosa for an Alabama football game? Prepare for a mostly rural two-lane trek through the state’s Black Belt region. Mobile to Huntsville? Yes, I-65 is a four-lane interstate the entire way but was built going 50 miles out of the way so it would go through Montgomery.

Navigating Alabama is arguably more difficult than our neighbor to the west. But that does not mean Mississippi is prospering compared to Alabama.

According to the U.S. Bureau of Economic Analysis, as of May 11 Alabama’s gross domestic product, the total value of goods produced and services provided in the state over one year, was nearly $200 billion. That put the state at No. 27 among all 50 states and the District of Columbia. Farther down the list at $106 billion was Mississippi, at No. 36.

Despite all these infrastructure improvements in Mississippi, Alabama over the last five years has continued to outpace the Magnolia State economically.

Conventional wisdom suggests infrastructure is the name of the game for growing the economy. All over the country, the more liberal and progressive precincts tout high-speed rail.

There is much more required for economic growth than getting people, goods and services transported more efficiently. Education, natural resources, public safety — those are all parts of the equation as well.

Certainly, one can make the argument that getting home from Mobile to the peaceful suburbs of the Eastern Shore will increase productivity slightly. That, however, is hardly a significant enough economic gain to justify pushing a $1 trillion spending bill, the bulk of which the federal government probably will borrow.

It may make recruiting industry a little easier, but the state can create incentives more cost effectively through its tax code. Alabama, to its credit, has done just that to lure auto manufacturing to the state.

Once you get those companies to the state, you expand the tax base, which ultimately means more revenue for the government. And then it’s more feasible to take on infrastructure improvement.

In the meantime, it is important to keep in mind that if you build, it doesn’t necessarily mean they will come.