The nonemergency hotline, which was founded in 2003 during Bloomberg's first term, allows New Yorkers to get their questions answered about city agencies and services.
The mayor visited a lower Manhattan call center Thanksgiving morning to praise the workers and release the results of a new customer satisfaction survey.
The survey, conducted by CFI Group Inc., revealed that 83 percent of callers were satisfied, a jump of 4 percentage points from the baseline set in 2008.
"We have the best workforce in the world, and the customer satisfaction survey of our 311 call takers is just the latest example of that," Bloomberg said in a statement released Thursday.
The 311 center's mark was also 11 points above the federal government average for call centers and six points ahead of the private sector average.
The center handles 50,000 calls a day on average and has received more than 170 million calls since its inception. Its website, which is available in more than 50 languages, averages 12,000 visits a day.
The hotline was one of Bloomberg's first landmark initiatives. The billionaire media and financial data mogul prides himself on making statistical-based decisions in the private sector, and he wanted to bring a similar mentality to the city's government. The reports generated by 311 allowed the city to adjust its responses to various complaints.
The 311 line consolidated more than 40 separate city information lines into one place and has been widely imitated in other cities. It is available 24 hours a day.
At the end of December, Bloomberg, a Republican-turned-independent, will leave office after 12 years. Mayor-elect Bill de Blasio, a Democrat, has praised the 311 system and plans to maintain it.