5G coverage compared: AT&T, T-Mobile, and Verizon tested on rural country roads

At a glance:

• T-Mobile was the only carrier to pull in a standalone 5G signal, capturing it nearly 90% of the time during a 15-hour rural road trip through Iowa and Wisconsin.
• Verizon led in overall network level (signal bars) and signal strength, with AT&T close behind in second place across both metrics.
• All three major US carriers showed notable coverage gaps on country roads and farmland, with southern Wisconsin being the only zone where complete internet failure was experienced.

The test setup and route

Adam Doud of ZDNET took a three-day road trip through rural Iowa and Wisconsin to benchmark 5G and LTE coverage for all three major US carriers: AT&T, T-Mobile, and Verizon. Unlike previous tests that followed interstates between major cities, this trip deliberately stuck to country roads and farmland to see how carriers perform where population density is lowest. The route ran from the Chicago area southwest to Douds, Iowa — an unincorporated community with a post office and a train station from the 1800s — then north through Platteville and Janesville in Wisconsin before returning home to the Chicagoland area.

The testing rig was upgraded from previous trips. Three identical Samsung Galaxy S26 Ultra units replaced the Google Pixel 10 Pro phones used on earlier runs. One S26 Ultra was provided directly by Samsung; the other two came from AT&T and T-Mobile respectively, all running on carrier-provided eSIMs. A ratchet-strapped PVC mount clamped to a tripod held all three phones in view from the rear window, and power came from an Anker Solix C1000 portable station with three USB-C ports and five AC outlets. nPerf served as the continuous performance-monitoring tool, and it crashed far less frequently on the S26 Ultra than it had on the Pixel 10 Pro during the Nashville trip.

5G coverage results

After requesting a full data dump from nPerf, Doud ended up with over 52,000 data points spanning the three carriers across the entire 15-hour journey. The data tracked three metrics per carrier: network type (LTE, LTE Advanced, standalone 5G, and non-standalone 5G), network level (essentially signal-bar count), and signal strength (measured in negative decibels, where a higher number — closer to zero — is better).

T-Mobile was the only carrier that recorded any standalone 5G signal at all. Non-standalone 5G, which relies on 4G infrastructure to establish connections, carries higher latency and is widely regarded as a stopgap rather than a true 5G deployment. T-Mobile delivered standalone 5G nearly 90% of the time it was available — a margin so large that neither AT&T nor Verizon came close in the 5G category.

Network level and signal strength

Verizon won the network-level comparison convincingly, maintaining the highest bar count for a significant portion of the trip. AT&T finished a not-too-distant second. None of the three carriers delivered excellent signal strength overall, but Verizon again led that metric, logging a good (though not outstanding) signal roughly 44% of the time. AT&T and T-Mobile trailed only slightly behind in signal strength.

The takeaway is a split result: T-Mobile dominated the 5G category by a wide margin, but Verizon and AT&T provided stronger and more consistent signal levels across the board. For anyone living away from an interstate, the picture is mixed — no single carrier clearly won every metric.

Real-world experience on the road

On the drive to Iowa City, Doud was a passenger and had pre-downloaded podcasts, so real-time connectivity was not critical. On the return leg, however, he tethered to his personal T-Mobile phone (an Oppo Find N6 not intended for US networks) to work remotely. Southern Wisconsin was the only stretch where the internet dropped out entirely. In the farm fields of Wisconsin, productivity stalled for roughly 20 minutes total across two separate occasions — annoying but manageable.

Notably, T-Mobile — Doud's personal carrier — recorded a network level of just one bar for 52% of the entire trip. While anecdotal, that figure underscores the inconsistency that can surface once you leave major corridors. The author acknowledged that had he been using a T-Mobile phone as his daily driver for the trip rather than just tethering, the experience might have felt more concerning.

What this means for rural connectivity

The core finding is blunt: if you live off the interstate, every major US carrier will struggle at times. The glossy "fastest network" marketing campaigns do not reflect the experience of rural and semi-rural users. All three carriers showed clear weaknesses once the test moved away from highways and metro areas. There is still meaningful work ahead for network buildout in low-density regions, though the situation is not as dire as some might expect — total connectivity blackouts were rare and brief.

For consumers choosing a carrier with rural coverage in mind, the data suggests weighing priorities. If standalone 5G matters most, T-Mobile is the only real option today. If consistent signal bars and strength are the priority, Verizon holds an edge. AT&T sits in the middle ground. None of the three is a bad choice, but none is a perfect one either — at least not yet.