FedEx courier Bob Hazelton knows South Boston inside out. A 19-year veteran of the company, he winds his way easily through the busy streets, following whatever route he thinks will let him make 100 or more daily stops most efficiently.
At this time of year, however, the routine changes. Hazelton is more aware of people who don’t seem to belong on a certain corner. He scans the area before deciding to leave a package at the front door. He may turn left where he usually turns right.
“During the busiest season, you try to mix it up a bit, just in case you’re being followed,’’ he said.
Since retailers first took to the Internet, the holiday season has created a shipping frenzy in November and December. This year, however, record numbers of consumers are heading to their nearest computers to do their shopping.
Thursday will be the busiest package-delivery day for the Postal Service as well as for UPS, which expects to distribute 28 million packages globally, up from 27 million last year. Its rival FedEx experienced its busiest day ever on Dec. 10, with some 19 million packages moving through its system worldwide, a 10 percent increase over last year’s peak day.
With this e-commerce boom, shipping companies must also grapple with the annual influx of package thieves who snatch newly delivered parcels from doorsteps and building lobbies. This year is no exception.
“Every year we deal with holiday theft,’’ said UPS spokeswoman Natalie Godwin. “Criminals will follow behind the truck.’’
Three women were arrested in Stoneham earlier this month for allegedly following a delivery truck and pilfering the packages it left for customers. Similar thefts have been reported in several other places, including Cambridge, Wellesley, and Southborough.
For the police, watching for such crimes can be tricky, said Deputy Superintendent Jack Albert of the Cambridge Police Department.
Last year, thieves concentrated on certain parts of Harvard and Central squares, Albert said. Police distributed flyers throughout the neighborhoods and passed on alerts to building managers.
But when thieves are not working in an area that they are known to target, it is difficult to know where they will strike next, Albert said. This year, there has been no pattern detected, he said.
“We do put out extra patrols during the holidays, but it is very difficult to patrol for packages,’’ he said.
UPS tackles the problem, in part, by using technology, Godwin said. The company’s new online My Choice service sends customers free text or e-mail alerts 24 hours before a package is scheduled to arrive.
Those using the basic service can reschedule the delivery, redirect it to another address, or have it delivered to a UPS retail location for a $5 fee.
The premium service, which costs $40 a year, gives members these options at no additional charge and lets users track their shipments and provide instructions to leave parcels on a back porch, in a garage, or in any other designated spot.
FedEx offers the option of having packages delivered, at no additional charge, to one of the company’s locations, rather than to a customer’s door.
Drivers are trained to watch out for vehicles that may be following them and to assess whether a delivery can be made securely, said Patti Yandle, a manager at the FedEx station in South Boston.
“It is his discretion whether it is a safe place to leave a package,’’ she said.
It is a decision that couriers will be making more than ever this year.
Online spending between Nov. 3 and Dec. 10 was up 13 percent over the same period last year, to a record high of $29.2 billion, according to a report released last week by the digital business analytics firm comScore.
To deal with the holiday rush, FedEx adds hours to the schedules of part-time drivers that it has hired throughout the fall, and full-timers work a bit harder.
“There’s no vacation, no scheduled time off,’’ Yandle said. “We have everybody here unless there’s an emergency.’’
UPS follows a different strategy, adding about 55,000 seasonal employees to its US workforce of 322,000, company spokeswoman Godwin said.
Some online sellers are also adding options that increase the security of deliveries.
The Amazon Locker program lets buyers have their purchases delivered to a secure locker in a retail store, to be picked up at the buyers’ convenience.
The Boston area does not yet have any lockers available, according to an Amazon.com search.
However, Framingham-based Staples Inc. recently said that it will start hosting Amazon Lockers in some of its stores, in a test of the concept.
For FedEx driver Hazelton, though, the most satisfying part of his job is putting a package directly into the hands of an eager recipient — after he has picked the safest route.
“You hear that every day — ‘I’ve been waiting for this!’ ’’ he said. “It is knowing you did a good job.’’