Usually not the way people fear. Most modern fiber construction uses directional boring that passes underneath lawns, driveways, and sidewalks — crews work in the utility easement along the street, and the visible disturbance is typically a small pit or two, some marking paint, and a patch of restored grass.
Where crews are allowed to work
Fiber mainline goes into the public right-of-way or utility easement — usually the strip along the street or alley that utilities have always had legal access to, commonly the first several feet of what looks like your front yard. Crews don't need your permission to work there, though good contractors knock, hang notices, and answer questions.
The colorful paint and little flags that appear first aren't the fiber crew's — they're the 811 locate marks showing where existing gas, power, and water lines run so nothing gets hit.
Boring under, not trenching through
In finished neighborhoods, crews use horizontal directional drilling: a steerable drill enters at a small pit, travels under your yard at several feet deep, and surfaces at the next pit — grass, driveways, and mature trees stay intact above it. Open trenching mostly appears in new construction or open ground where there's nothing to preserve.
What 811 does not mark: private lines you or a previous owner added — sprinkler systems, landscape lighting, invisible dog fences. Tell the crew or the contact on the door hanger where yours run; good crews ask, pothole carefully, and fix what they hit.
Restoration, and what to do about damage
A finished job leaves compacted backfill, replaced sod or fresh seed, and patched concrete — restoration crews often follow the construction crew by a week or two, so a rough-looking yard mid-project is normal. If something is damaged or restoration disappoints, note the contractor name from the door hanger or truck, photograph it, and call the ISP building the network — restoration is part of the contract, and reputable contractors return. That accountability chain is exactly how we run our own builds.