Verizon (VZ -1.54%) has once again swept the twice-yearly RootMetrics Mobile Performance in the United States report on a national level. The company did tie with Sprint (S) and AT&T (T -1.22%) in the "text" category, but the company lost ground at the metro level in the study that covers the first half of 2017.

"The bigger story exists at state and metro levels where AT&T, Sprint, and T-Mobile [(TMUS 1.23%)] make significant strides," according to an emailed statement from RootMetrics. "Metro-level performance provides the strongest gauge of a network for consumers."

Since many people don't travel extensively, or travel within limited areas, or travel only a few times year, the most important thing is how their wireless network works wherever they spend the most time.

A drawing of a man holding a cellphone with a picture of a person on it that is linked to pictures of other people.

Gains are being made by its rivals, but Verizon still has the top wireless network. Image source Getty Images.

Gains are being made

RootMetrics defines metro areas as not just city centers, but also residential suburbs, business districts, recreational areas, and the highways that connect them. It tests network performance in all those areas and while Verizon still won, it scored fewer first place wins than in the previous period while AT&T, and to a much-lesser extent, T-Mobile scored more.

  • Verizon earned 617 first-place awards, down from 658 in the second half of 2016.
  • AT&T scored the biggest improvement, going from 372 first-place wins in the previous testing period to 396 this one.
  • T-Mobile added one first-place victory, going from 270 to 271.
  • Sprint lost ground, dropping to 211 first-place awards, down 35 from the second half of 2016.

First-place awards are only part of the story as RootMetrics noted that "AT&T and T-Mobile made big speed and reliability improvements in metro areas." Even Sprint, which appears to be the least successful carrier in the current report, saw "significantly boosted data speeds and reliability at the metro level," according to the independent research firm.

T-Mobile has questioned the report

To come up with its score, RootMetrics testers drove over "275,000 miles while testing performance on highways and in big cities, small towns, and rural areas across the U.S." In total the company collected approximately "4.7 million test samples while driving and at more than 8,800 indoor locations."

It's worth noting that while Verizon has run television commercials based on RootMetrics' results, T-Mobile CEO John Legere considers them biased. He sent an email to the media in February 2016 about the research company turning off his company's Voice over LTE feature, "that is on every single phone we sell. VoLTE handles roughly 50% of calls made on the T-Mobile network," he wrote.

Legere also questioned exactly how independent the research firm is, asking "Do we have to pay RootMetrics millions like the other carriers do to get them to stop deliberately turning off significant portions of our network and skewing results during their drive tests? Coincidence? Doubt it."

RootMetrics said in an email to The Motley Fool responding to Legere's complaint that anyone can purchase its highly detailed data, but that is not connected to its results. RootMetrics now tests VoLTE and has since the first half of 2016.

What does this mean?

Verizon can still accurately say it has the best network, but that claim no longer means as much as it once did. Wireless network reliability overall has improved and that has given the public more viable choices.

For many people, AT&T, T-Mobile, and even Sprint offer a good, or at least good enough, experience. Verizon is the leader with AT&T the clear No. 2, but for a lot of people, T-Mobile and Sprint have improved to the point where they are reasonable options, especially since they are the cheapest of the four major carriers.