Network benchmarking company Rootmetrics has been going through data from its testing during the first half of 2018 and concluded that increasing network data speeds is a clear area of focus for all of the major U.S. carriers.

Rootmetrics dove into its data for the Washington, D.C. metro area, collected in early April, and found that Verizon has significantly improved its network performance there, snagging a sweep of Rootmetrics’ category wins for the first time since 2016. Rootmetrics said that although all of the carriers notched network reliability ratings of 98% or more, Verizon won that category outright. The carrier also won the data performance category,  although all of the carriers saw improvements in that area. T-Mobile US clocked the fastest upload speed of 19.5 Mbps, with top median download speeds from T-Mo, AT&T and Verizon ranging between 29.5 Mbps and 31.2 Mbps. Sprint lagged behind those three but still had “big data performance improvements,” Rootmetrics said, increasing its median download speed from 10.2 Mbps to 15.4 Mbps.

“Our analysis of the mobile experience in Washington, D.C. has one big takeaway – data performance is a top priority for the carriers,” said Doug King, director of business development at RootMetrics, in a statement. “Although Verizon takes the top spot in this category, it’s clear that all the networks are making investments to increase speed and reliability, with improvements across the board.”

Rootmetrics said that the testing, using off-the-shelf devices purchased from carrier stores, was conducted between April 2-6 at 119 locations, with more than 2,000 miles of drive-testing.