On Wednesday, I wrote about an iPhone and Android app that tells you how strong a cell carrier’s data and voice services are in your area. The developer, RootMetrics, also posts reports about the overall state of wireless in a variety of major markets, and I wrote that Houston wasn’t among the cities featured on a page listing them.

But it turns out there is indeed a report for Houston. RootMetrics released one at the end of May [PDF] that examines the quality of service in Houston provided by AT&T, Sprint, T-Mobile and Verizon. While the report highlights the companies’ 4G data networks, it also provides some eye-opening statistics about voice and texting services as well.

RootMetrics gathered the data for the report in two ways, according to spokesperson Ann Marie Ricard. Some of it was pulled from the reports generated by users of its Coverage Map app. The research company also rolled into town and spent a week conducting tests here, prowling the streets with off-the-shelf Android smartphones, to create the report. [Note: RootMetrics’ spokesperson emailed to clarify that the city reports do not include data from the app. However, an interactive map into which users can enter a city name does include data from both processes.]

Among its findings: Verizon not only has the fastest 4G network in Houston, but it’s also faster here than in other markets RootMetrics has tested. Verizon’s LTE network kicks some serious butt, according to the report:

We recorded average download speeds that were over 3 times faster than the 2nd fastest download network (Sprint) and average upload speeds nearly 5 times faster than the 2nd fastest upload network (T-Mobile).

Where does AT&T fall in that ranking? Unfortunately, at the time RootMetrics was in town, the only AT&T phone that worked with Ma Bell 2.0’s 4G HSPA+ data network was the Infuse 4G, and it needed a not-yet-delivered firmware update to achieve true 4G speeds.

Verizon’s LTE network was also deemed the most reliable, with devices able to connect to it 97 percent of the time. AT&T was next with 96 percent, followed by Sprint with 87 percent and T-Mobile with 76 percent.

RootMetrics’ report notes that Verizon’s network had just been launched, with few customers and not many devices accessing it. As traffic on the LTE network increases, speeds may decrease, the report says.

The company also measured voice call service, and its tests determined that T-Mobile had failed calls 12 percent of the time, followed by AT&T at 3 percent, just over 1 percent for Verizon and less than .4 percent for Sprint. In terms of dropped calls, Houston did much better than many other markets tested, with no carrier dropping calls more than 1.3 percent of the time.

RootMetrics also checked SMS performance, something often overlooked in other carrier performance tests. The lowest was T-Mobile, with a text delivery time of 6.3 seconds, while AT&T pulled up the rear with a 15.8-second delivery time.

RootMetrics takes all these data points and uses them to generate an overall ranking. Verizon comes out on top with a RootMetrics Score of 86.2 percent.

Does RootMetrics’ report jibe with your experience with your current carrier?