Maryland Gov. Martin O’Malley (D) said Tuesday that his administration is “still having conversations” about whether to make another run at raising more money for transportation projects in the upcoming legislative session.

During the last 90-day legislative session, O’Malley proposed applying the state’s 6 percent sales tax to gasoline. It is estimated that the move will raise more than $600 million a year for road and mass transit projects, including the planned Purple Line in the Washington region and Red Line in Baltimore.

But the bill did not go anywhere in either chamber.

“There will come a time when it no longer makes any sense to put any money into the Red Line or Purple Line if the General Assembly wants to pretend we can fund our transportation challenges based on a 30-year-old flat tax on gasoline,” O’Malley told reporters Tuesday.

Under current forecasts, the state has no money for any highway construction after fiscal 2017. Ditto for construction of the Red and Purple lines, or the proposed Corridor Cities Transitway along the I-270 corridor in Montgomery County.

The next 30-day legislative session opens Jan. 9.

The last time lawmakers raised the state’s 23.5-cent gas tax was 1992. The gas tax remains the state’s largest source of funding for transportation projects.

While speaking to reporters, O’Malley also raised the possibility of raising the state’s general sales tax from 6 percent to 7 percent and earmarking the additional revenue for transportation.

He said that is an idea “that some others brought up” last session. O’Malley suggested that it might be less unpopular than targeting prices at the pump.

“I’ll bet if you asked anyone at any community meeting which of those two alternatives they prefer ... most people would rather see it spread out over that 1-cent in the sales tax,” he said.