STILL waiting for that passport you applied for this summer? The State Department says it’s on its way. The time it takes to process a passport has returned to the usual six to eight weeks, a welcome change for many Americans whose travel plans were upset this summer as the department’s staff worked through a substantial backlog.

The crush of applications, caused by a new requirement that United States citizens present passports when traveling by air to and from Canada, Mexico, Bermuda and countries in the Caribbean, doubled the turnaround time to 12 weeks from six and disrupted many people’s travel plans. At one point in June, the State Department reported as many as 2.95 million passport applications were pending, even as more were flooding in.

To cut into the backlog, the department hired back retirees, sent extra employees to overwhelmed passport processing offices and scheduled extra shifts. It also suspended the new regulation, which ends a preferred status for travel to and from several close neighboring countries: travelers were allowed to enter the United States by air with just government-issued photo identification and proof of having applied for a passport.

Starting Oct. 1, nearly anyone coming into the United States by plane — including Americans returning from popular fall and winter vacation destinations in places like Jamaica or Mexico — will need to present a passport at the airport. Those who don’t, the Department of Homeland Security says, will have to go through additional scrutiny to verify their citizenship, a procedure that will cause delays — how long is anyone’s guess.

American citizens who left the country under the temporary travel accommodation before Oct. 1, using just government-issued ID, like a driver’s license, and a State Department proof of passport application, will be readmitted with these same documents, but anyone who sets out after Sept. 30 will have to have a passport to return by air.

The federal government’s efforts to meet the demand for passports and get processing back under control seem to be paying off.

“I sent in my application in July 2007 and have already received the renewed passport," said Linda Carrubba, an executive assistant at a research institute in Somerville, Mass., who plans to travel to Uruguay next year. “My co-worker sent in an application in January 2007 and didn’t get hers until July. So things apparently have speeded up."

Last month, the government issued a record 2.5 million passports, up from about 1.2 million in August 2006.

Rush services, companies that charge anywhere from $130 to $200 on top of passport fees to work with the government’s regional passport agencies to process applications in as little as 24 hours, say wait times are much less than they were early this summer. “We definitely have noticed less demand, and that has clearly resulted in less difficulties occurring,” said Rob Smith, director of the National Association of Passport and Visa Services, a trade group for these expediting companies.

This month, as travel subsides after the summer peak, is one of the best times to apply for or renew a passport. The first six months of the year are usually the busiest, Mr. Smith said, “but it tends to wind down a bit in the fall.”

There’s another reason to consider applying for or renewing a passport now. The new requirements for Americans coming home from neighboring countries will be extended to land and sea travelers, possibly by next summer, according to the Homeland Security and State Departments. The proposed rules require most of these travelers to show either valid American passports or approved passport alternatives like a $50 Nexus card, issued to prescreened travelers under a joint program operated by the United States and Canada.

The rules allow a few exceptions. An American on a cruise that begins and ends in the United States will be able to come back home with just a government-issued photo ID and a birth certificate, consular report of birth abroad or certificate of naturalization. Americans and Canadians younger than 16, and those 18 and under traveling in designated groups, as on a school trip, will need the birth or naturalization documents, but not a government ID.

On the Canadian border, where both Americans and Canadians are used to being able to drive into the United States, or come in by boat, after simply giving an oral declaration of citizenship, a big change is coming Jan. 31. During a transition period between then and the full imposition of the new rules, these travelers will need to present government-issued photo ID, and proof of citizenship, like a birth certificate.

FEARING more confusion and passport delays, several travel trade groups, including the National Tour Association, and legislators have been pushing for delays in some of the tighter rules. And some border states are proposing alternatives to passports. Washington State, for example, is developing a so-called enhanced driver’s license, which would cost $15 more than a standard license and provide both identification and proof of citizenship.

Ultimately, however, the new regulation is expected to drive an even greater influx of passport applications as more Americans learn about the new rules and master the procedures for applying: Bring your application to a place that accepts them, often a post office or library, with proof of citizenship, photo ID, two photos and $97. For a child, bring along both parents, or notarized permission to obtain a passport from a missing parent. Further details are at www.state.gov.

Regardless of how quickly the changes play out, the best way people without passports can avoid any possible backlogs or problems later is to apply at least a couple of months before they plan to take any foreign trips.

“If they are traveling outside the U.S. anytime in the near future, N.T.A. is encouraging travelers to obtain their passport now,” said Randy Julian, chairman and chief executive of the National Tour Association. “It’s certainly the safest course of action. It will prevent possible confusion and possible border bottlenecks later on.”