PHILADELPHIA — In the videotaped message, Pope Francis issues a personal invitation to pilgrims — “See you in Philadelphia!” — but it remains an open question whether the massive crowd organizers have predicted will turn out to see him.

Despite an “I’ll be there” marketing campaign, a rollback of some travel restrictions and an increase in hotel bookings, signs remain that estimates that up to 1.5 million people would be in town for the pope’s outdoor Mass on Sunday may be too high.

“I look forward to greeting the pilgrims and the people of Philadelphia when I come for the World Meeting of Families,” the pope said in English. “I will be there because you will be there!”

The pope’s appeal was the culmination of a monthlong effort by planners to turn around the public perception that security and travel restrictions — including initial warnings, since dialed back, that visitors would have to walk miles — had made it too much work to come see Francis.

What’s more, the Secret Service said Friday that the mile-long Benjamin Franklin Parkway, the secured site of the pope’s two biggest events, would only fit about 250,000 people. Other visitors will have to watch on jumbo TV screens near the parkway or in other locations, which church planners said was always the plan.

Heading into the final week before the pope’s U.S. trip, hotels in Philadelphia had more than 1,000 rooms available. Regional transit agency SEPTA had sold only about a third of its papal visit rail passes, and the southern New Jersey commuter rail, PATCO, less than a sixth. PATCO even said it would let pilgrims buy same-day tickets if they want. Charter bus reservations are also a fraction of what was projected.

Philadelphia Archdiocese spokesman Ken Gavin said “The final message is, ‘Come, be here and you will always be glad you (did).”’