When local voters approved a new five-year transit tax in May 2014, infusing millions of additional dollars into the Ann Arbor Area Transportation Authority's budget, the promise was more buses, more places, more often.

And the expectation was that having more buses running longer hours, making more frequent trips and reaching new destinations would mean more riders.

But even with a 9.1 percent increase in service hours last fiscal year, which ended Sept. 30, the AAATA saw local fixed-route ridership go down by 0.8 percent, according to an Ann Arbor News analysis of agency reports.

The AAATA still clocked 6.3 million local fixed-route passenger trips from October 2014 through September 2015, but that fell far short of the nearly 7 million trips projected, and it was 48,882 trips down from the previous year.

The AAATA's ridership has dropped off even more since implementing a second wave of service improvements last August, including expanded weekend service to complement the longer evening hours.

Year over year, local fixed-route ridership was down 6.3 percent in September and 8 percent in October, according to the most recent reports publicly available.

An AAATA bus pulls out of the Blake Transit Center in downtown Ann Arbor on Jan. 15, 2016.

So, how has bus ridership gone down while the AAATA has been busy expanding services?

AAATA CEO Matt Carpenter, who started on the job last June, believes lower gas prices have more people hopping in their cars again.

"Low fuel prices are depressing ridership in transit agencies across the nation," he said. "This is not a local phenomenon. It's very much an artificial situation because of the price of oil, which we know is a very political situation that's coming out of the Middle East. So, it's a temporary situation."

Carpenter said he remains optimistic ridership will bounce back, and he believes the next round of service improvements in May will help.

AAATA leaders point out it's only weekday ridership that is down. They say new weekend services have been well received.

"For example, Sunday service has been expanded. I think ridership is up 25 percent there," Carpenter said. "Saturday service is up 10 percent. So, when we have restructured in this environment, ridership has increased, so that's promising."

He added, "Where we're seeing our ridership be a little soft ... is in our weekday commuters, which makes sense. These are the folks who, if the price of gas goes down, they're the most likely to drive a little bit more instead."

Carolyn Grawi and Mike Garfield, two of the leaders of the transit millage campaign in 2014, said on Friday they hadn't seen the ridership numbers, but they've both heard anecdotally that the new services have been well received.

Grawi, director of the Ann Arbor Center for Independent Living, said there are people from the disability community who have access to transit services they didn't have before, and those who previously had access now have wider access.

"I, myself, have been able to gain access to attend meetings and events in the expanded service area," she said. "For example, being able to get to and from the Ypsilanti Marriott so I could do my job."

Ann Arbor residents Lou Glorie and Ted Annis, two critics of the transit millage campaign, had a different take.

Annis, a former AAATA board member, said he considers the ridership dips proof the AAATA's statements and projections are unreliable.

"It's not surprising," Glorie said. "Because I believe the AAATA is more oriented toward commuters than ridership within town. And I can tell you, on our Nextdoor Water Hill site, there have been conversations about it recently, and people are saying (the bus service) just doesn't go where they want it to go, and if you have to make two or three switches to get where you want to go, it's not worth it."

AAATA spokeswoman Mary Stasiak said fixed-route ridership for November was down 0.8 percent. A full report for November isn't available yet.

For the first two months of the fiscal year, October and November, ridership still was down 4.6 percent, while service hours were up 5.6 percent, Stasiak said.

Stasiak said it's significant to note that overall ridership is actually up 2 percent when excluding University of Michigan riders and riders using go!passes, which are the unlimited bus passes made available to downtown Ann Arbor employees.

That suggests there are fewer downtown employees and U-M students and staff riding the bus.

AAATA leaders believe changes in where people are living have played a role in that, with a large supply of new housing in the downtown having come online last August, including the university's new 630-bed graduate student dorm.

"We think there has been some relocation of housing, university housing, that shifted some of our ridership base around a little bit," Carpenter said. "Which is good in some respects, that maybe people are closer to where they need to be, so they can walk to wherever they're going, but it also means our market got a little bit smaller."

As bus services have increased and ridership has ticked down, the AAATA's costs per passenger have gone up.

Total operating expenses per passenger were reported at $4.97 last fiscal year, or $4.11 if just looking at fixed-route service -- up from $3.71 the year before.

That's nearly an 11 percent increase in cost per fixed-route passenger, which is a measure of cost efficiency that's trending in a negative direction.

Carpenter said the agency expected its costs per passenger would go up when adding more off-peak service hours on nights and weekends, but he argues there's still a lot of value in providing those new services.

"Those are really critical toward allowing people to have a car-free lifestyle, to know that they can hop on the bus later, or they can stay an hour later with their friends, and that the service will be there in an hour," he said. "Unfortunately, it is a lower-use time. We knew that going into it, so we knew there would be additional cost."

Under the 0.7-mill tax approved for five years in May 2014, the owner of a $200,000 home is paying an extra $70 per year.

The total number of AAATA fixed-route service hours went up from 200,948 to 219,272 last fiscal year, which ran from October 2014 through September 2015, the first full fiscal year since services started to expand under the new tax.

When the tax was approved with 71 percent support from voters in Ann Arbor, Ypsilanti and Ypsilanti Township, it was projected to generate nearly $4.4 million in new annual revenue for the AAATA, helping to fund a 44 percent expansion of services over five years. The next wave of improvements comes in May.

"I think we're going to win back a good chunk of riders with the service in May, simply because it's going to be faster and more direct," Carpenter said, noting the changes include a major route reorganization breaking up some of the longer loop routes.

When gas prices go back up, Carpenter said, more people will look to the AAATA and go, "Oh, wow, this is a whole lot better than I remember."

"I'm pretty confident," he said. "Obviously, we're monitoring it closely. We're keeping a close eye on those numbers. But it's a nationwide -- probably global --phenomenon that's largely driven by this artificial fuel price thing."

Carpenter's optimism is reflected in agency's budget, which predicts there will be more than 7.9 million fixed-route passenger trips this fiscal year. That would be a 27 percent jump, or 1.6 million more rides, if it happens.

Agency leaders said being so far off on ridership projections this past year didn't have much effect on the agency's finances. They still managed to balance the budget without making any significant cuts or raising fares.

Passenger revenue, which the agency had projected would be close to $6.3 million last fiscal year, actually came in at about $5.9 million.

Federal operating assistance also came in much lower than expected, projected at $6.1 million to start the year, and ending up closer to $4.4 million.

Altogether, while the agency originally projected $38.7 million in total revenue, it actually came in at $35.6 million. But the same happened with expenses, which were projected at $37.2 million and ended up at $35.4 million.

The AAATA now has a $40 million operating budget for 2015-16 and is projecting passenger revenues ticking up to about $6.5 million.

Ryan Stanton covers the city beat for The Ann Arbor News. Reach him at ryanstanton@mlive.com.