WASHINGTON (AP) — Tea party fervor has surged and waned in the past four years, Occupy encampments are long gone from parks in the nation's capital, and the crowd for President Barack Obama's second inauguration figures to be significantly smaller than the record-breaking turnout of 2009.

But spectators can still expect the customary tight security long associated with the event — not to mention protesters for assorted causes.

City and federal officials are implementing measures intended to prevent calamities, such as a terrorist attack, and to address more mundane concerns, such as slow-moving security lines and cold weather. Flight restrictions are in place in the skies over Washington, with extra security on the city's waterways. Spectators will be limited in where they may drive and what they may bring. The Secret Service, the lead law enforcement agency for the Jan. 21 event, isn't revealing specific precautions, though tactics in the past have included trained counter-snipers, bomb-sniffing dogs and surveillance cameras with feeds streaming into a command center.