With construction on the Big Dig scheduled to end this spring after 15 years of work, the Massachusetts Bay Transportation Authority is looking for new ways to keep riders on the buses and subways, but not everyone has been satisfied with the changes, as the newly implemented Charlie Card is causing public transportation riders headaches.

“Now that the Big Dig project is winding down, the T has to work hard to attract customers that may go back to driving,” MBTA spokesman Joe Pesaturo said. To appeal to T riders, the MBTA has been renovating stations, buying new T cars and buses and installing new mechanized fare booths, which Pesaturo said has increased business on the T.

But the MBTA’s most highly-publicized change is the Charlie Card. Eighteen stations currently issue and use the Charlie Ticket — the preliminary version of the Charlie Card — which is a paper ticket similar to New York’s MetroCard that all riders must buy from machines before boarding the T. Pesaturo said riders are obligated to use the Charlie Card at these stations, but they cannot be used at other stations.

Sargent College graduate student Brooke Aldrich, who rides the Green Line everyday, called the Charlie Tickets “totally inconvenient” because they are only available at certain stations right now, none of which she normally uses.

“I’ve used them to come home from the airport before, and I can see how they’d be really confusing to out-of-towners,” she said. “They run out of money when you don’t expect them to.”

School of Management and College of Arts and Sciences sophomore Hil Duran said she thought the Charlie Tickets system is “dumb” because it creates too much confusion for riders.

“I have friends who will buy them and put $5 on them,” she said. “Then they still end up buying tokens and spending even more money because you can’t use the pass everywhere.”

Pesaturo said the Charlie Ticket system will be more reliable when the operation is completely installed.

“Once the Charlie ticket is available at all stations and lines, it will make a big difference for flexibility of paying and ease of riding,” Pesaturo said, adding that riders also now have the chance to buy weekly or monthly passes at the stations with Charlie Tickets — an option that was previously only available at a few downtown stations. Pesaturo said the Charlie Ticket capability is scheduled to be installed in every station by 2007.

Pesaturo added that the MBTA changes were made in consideration to the near completion of the Big Dig, one of the largest and most complicated infrastructure ventures in U.S. history. After 15 years of construction, most of the roads, tunnels and bridges are now open for traffic according to the Massachusetts Turnpike Authority website.

According to an economic report released by the Turnpike Authority in February, some segments of the new highway system are seeing 101 million travelers per year — a 38 percent increase since 1994 — and Turnpike officials expect an even greater number of tourists and commuters on the roads as construction is completed.

However, not everyone is convinced the Big Dig’s completion will cause the number of T riders to decrease dramatically.

School of Education senior Emily Baumbusch, who has bought a monthly T pass during her four years at Boston University, said she does not see the completion of the Big Dig as an incentive to drive.

“I’ve always lived in a big city, so I’m sure there’ll always be construction going on and delays,” she said.