Though IndyGo on Monday announced plans to ditch its express bus from Greenwood because of low ridership, the Indianapolis bus service noted today other more popular suburban routes to Fishers and Carmel could end as early as next year.

All three routes – plus an express bus from Downtown to the Indianapolis International Airport – were funded by a one-time, $4.5 million federal grant to reduce pollution and IndyGo said from the beginning that it could fund the bus lines for about three years.

Money not going toward the Greenwood route could be redirected to the other three routes, or another option would be to start bus service to Hendricks County, which IndyGo officials had considered before ultimately choosing Greenwood in 2008.

Trevor R. Ocock, IndyGo’s vice president and chief operating officer, told the Greenwood City Council on Monday that the Central Indiana Regional Transportation Authority and the Indianapolis Metropolitan Planning Organization, which administer the grant, will explore options for the remaining funding.

Jenny Brown, an IndyGo spokeswoman said the agency was exploring whether money for the Grenwood line could be applied to the north suburban routes to extend their lives.

“I think it’s an open field right now,” IndyGo spokeswoman Jenny Brown said today. “There’s a lot of discussion right now on what to do with the money.”

The Fishers, Carmel and airport express routes are not in danger of being pulled until the grant money runs out sometime next year, Brown said.

Fishers bus started in October 2007; the airport route, November 2007; the Carmel bus, March 2008; and the Greenwood route, March 2009.

The Fishers bus, the most popular, peaked with more than 13,000 riders in July 2008.

But numbers have fallen dramatically as gasoline prices stabilized into the $2 range and the bus fare increased as ridership fell.

In August, one-way rides totaled 6,743 on the Fishers route, 4,604 on Carmel, 3,333 on the airport’s Green Line and 1,379 on Greenwood.

Morning trips from Downtown to the three communities are rare. A bus driver for the Carmel route recently said only two commuters ride from Downtown most days.

Greenwood officials had planned to use passenger fares – the service costs $3 each way – to cover its share, but low ridership made that impossible. Greenwood now owes $40,000.

“If it continued for 36 months, it could have gotten into the hundreds of thousands of dollars,” Brown said of Greenwood’s financial obligation. “I think it just came down to the need is just not there right now.”

The Carmel and Fishers services, in contrast, have paid for themselves through the fare box, Brown said.

IndyGo dedicated $1.8 million to the Carmel, Fishers and Greenwood routes, and required the local governments to pick up 20 percent of the operating costs. The routes are considered “demonstration projects” and another grant isn’t expected. Federal stimulus funds locally are being used to buy new buses and cover other capital costs, Brown said.

“We would like to get a source of funding and be able to keep these routes but our priority is Marion County,” Brown said.

IndyGo staff today informed riders that the Greenwood service would end. IndyGo will continue to offer a fixed-route service along U.S. 31 between Downtown Indianapolis and Greenwood.

“We’re hoping they made a lifestyle choice,” Brown said of the commuter express riders, “and they will convert to the fixed-route service.”