The city's top traffic cop, Superintendent Lucile Faycho, said the estimate was based on the number of attendees over the last six years.
Citing police estimates, local media said this year's festivities could draw a total of 17 million devotees nationwide, some seeking healing for illnesses and forgiveness for sins and others expressing gratitude for blessings.
The SC said it expects "difficulty of travel to and from the courts" in the city.
The figure includes those attending novena masses at Quiapo Church and also those who will join activities at the Quirino Grandstand.
"Filipinos who come to Quiapo... get a sense of being near the Lord, of the Lord touching them and of the Lord accompanying them... through hard challenges", Quiapo church parochial vicar Father Marvin Cruz told AFP.
In a frenzied display of religious fervour, men, women and children climbed over heads and shoulders and flung themselves at the centuries-old Black Nazarene that they say performs miracles.
Coronel noted that he submitted a recommendation to the Office of the Mayor for the imposition of a temporary ban of sale, and distribution of liquor and alcoholic beverages from 6 p.m. of January 8 to 6 a.m. of January10.
A sea of heaving, towel-waving humanity swarmed a black statue of a cross-bearing Jesus Christ in the Philippine capital yesterday as the Catholic faithful joined one of the nation's largest religious festivals.
The administration of Quiapo Church on Monday said 18 million devotees were expected to flood the streets of Manila during the procession or the Traslacion from Quirno Grandstand to the Quiapo Church basilica.
However, establishments catering to tourists may be exempted.
The procession of the replica images is set to begin on Sunday at 2pm at Quiapo Church.
Worshippers will walk through the streets - oftentimes barefoot - while following the statue's route for up to 22 hours.
Explaining the strong Filipino devotion, Monsignor Sabino Vengco, a prominent Catholic priest, told CNN Philippines: "People will suffer sickness, old age.so pain and suffering will always be there", he said.