As useful as 311 is to ordinary New Yorkers, the most intriguing thing about the service is all the information it supplies back to the city. Each complaint is logged, tagged, and mapped to make it available for subsequent analysis. In some cases, 311 simply helps New York respond more intelligently to needs that were obvious to begin with. Holidays, for example, spark reliable surges in call volume, with questions about government closings and parking regulations. On snow days, call volume spikes precipitously, which 311 anticipates with recorded messages about school closings and parking rules.