When planning a fiber build, aerial construction often looks like the obvious way to save money. The poles are already there. The route is visible. You don’t have to trench a road or install new conduit.

So the assumption becomes: aerial is cheaper than underground.

Sometimes it is. But not always.

The problem is that the real cost of an aerial route can be difficult to see on a map. You have to understand what is happening on the poles themselves. How tall are they? What is already attached? Is there enough clearance for another attachment? Can the pole handle the additional load? Will make-ready work be required? And, most importantly, how many poles may need to be replaced before the route can be built?

Those questions can change the economics of a fiber project very quickly.

One Pole Is a Problem. A Row of Poles Can Change the Route.

Consider a broadband provider that wants to attach fiber to an existing utility pole.

The pole has an issue and needs to be replaced. The utility may already have that pole scheduled for replacement, but that does not necessarily mean it will happen soon. Depending on the condition of the pole and the utility’s other priorities, replacement might be a year away, two years away or even longer.

The broadband provider may need that pole next month.

That is where the parties have to find a solution. The provider may agree to pay part of the replacement cost to have the work prioritized. In some cases, it may have to pay the full cost.

For one pole, that may still make financial sense.

But what happens when you encounter five? Or seven? Or an entire stretch of poles that require significant make-ready work or replacement?

At some point, the math changes.

The provider can look at those costs and say: We’re over budget. We might as well put this underground.

And sometimes underground is now the cheaper option.

This isn't just a hypothetical concern. The Pew Charitable Trusts reported that a major broadband provider returned federal Rural Digital Opportunity Fund awards covering tens of thousands of locations across four states because of unforeseen costs driven primarily by the need for extensive utility pole replacements.

That's an extreme example, but it demonstrates how significantly unexpected pole conditions can alter the economics of a broadband project.

The Decision Needs to Happen Earlier

The bigger issue, in my opinion, is not whether aerial or underground construction is inherently better.

It is when that decision is being made.

If you identify difficult pole conditions during high-level route planning, you still have options. You can adjust the route. You can evaluate underground construction. You can look for another engineering solution.

If you discover those conditions after the route has been fielded, engineered and permitted, changing course becomes much more expensive.

This is why I always encourage people doing high-level design to actually drive the route.

You may look at a map and see a row of utility poles going exactly where you want your fiber to go. But if those are 35- or 40-foot poles already carrying primary and secondary power facilities and multiple communications attachments, there may not be enough clearance for what you want to add.

A map also may not tell you how many telecommunications, cable or other broadband attachments are already occupying the communications space.

You don't really understand how busy that pole is until you see it.

As I often say, it’s nice and neat on the map until you walk it or drive it.

The Cheapest Route on the Map Can Become an Expensive Build

We saw the consequences of this on a large project covering roughly 170 miles.

The route had been established. It had been fielded and permitted. But when construction costs were finalized, the contractor’s per-foot price more than doubled from its initial estimate because of the actual conditions along the route, including hills, valleys and heavily wooded areas.

At that stage, the project owner was facing a difficult choice: find another contractor or redesign a route that had already gone through engineering and permitting.

That's very different from identifying those challenges during route planning.

The lesson isn't that aerial construction was the wrong choice. It's that the economics of a route cannot be fully understood from desktop design alone.

Pole Replacement Isn't Always the Only Answer

There is another mistake I see in this discussion: treating an overloaded or problematic pole as if there is automatically only one solution.

Sometimes the pole does need to be replaced. But depending on the circumstances, engineers may be able to consider other solutions, such as a bypass pole, an underset pole, crossarms, anchors or a change in construction type.

I've also seen a broadband provider take a completely different approach.

Instead of paying to replace existing utility poles or moving the route underground, the provider installed its own shorter communications poles on the opposite side of the road.

Why?

Replacing an existing utility pole isn't simply the cost of buying and installing a taller pole. Existing electric and communications facilities may need to be transferred to the new pole, and the old pole ultimately has to be removed.

At times, the company or municipality placing the new fiber may do the math and determine that installing its own communications poles is less expensive than the alternatives. That solution isn't going to work everywhere. That's exactly the point.

The objective shouldn't be to defend aerial construction at all costs—or to assume underground is the better answer.

The objective should be to find the most practical, buildable and economical solution for the actual conditions in the field.

Do the Pole Math Before You Commit to the Route

With the amount of broadband infrastructure still being planned and built across the country, getting these decisions right early matters.

Aerial fiber will continue to make sense for many projects. Existing utility infrastructure can provide an efficient path to reaching communities without the cost and disruption associated with underground construction.

But “aerial is cheaper” should not be treated as a rule.

Before committing to an aerial route, understand the poles. Understand the clearances. Understand the likely make-ready. Look at how many poles may need replacement and who is likely to bear those costs. And understand the terrain you're actually going to build through.

Then compare your options, because sometimes the cheapest aerial route on the map isn't the cheapest route to build.

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