Seeking an aggressive expansion of the District's Circulator bus system, a D.C. councilwoman on Wednesday proposed significant fare hikes that could double the cost of traveling along the five lines that crisscross Washington.

The recommendations from Ward 3 Councilwoman Mary Cheh, who chairs the council's transportation panel, would raise Circulator fares to $1.50 for passengers paying with a SmarTrip card. Passengers opting for a cash transaction would pay $2.

The current Circulator fare is $1 for adult passengers, though disabled residents and seniors can ride for 50 cents.

Cheh did not immediately respond to a request for comment about the hikes, which she estimated would add $1.7 million to the city's coffers every year, as her committee prepares to review her proposal at a Thursday hearing.

The fare increases would take effect in July 2014, and Cheh's draft report said the immediate revenues would go toward the Washington Elderly & Handicapped Transportation Service.

Beginning in October 2014, the extra money would be used to extend service to Adams Morgan, U Street, Shaw, Howard University, the National Cathedral and the Southwest Waterfront.

A spokesman for Mayor Vincent Gray said the administration would evaluate Cheh's recommendations.

"We are reviewing the councilmember's proposal," Pedro Ribeiro said. "However, the mayor has made it clear that he does not support raising fines, fees or taxes."

Ribeiro added: "The mayor has always said that the city can generate more revenue, but that it needs to do it by growing the economy, not by growing taxes or fees or fines." After Cheh's committee votes on her proposal on Thursday, lawmakers will take up the full budget measure on May 22 for a first vote. The council will likely send its final budget package to Gray in June.