LIKE POTHOLES during the lifetime of an administration, the ups and downs of Maryland's celebrated evaporating gasoline tax proposals are back in the news--with Gov. Harry Hughes now saying the taxes have got to go up. This, you may recall, is what he was saying some time ago, just months before he said that they wouldn't have to go up after all. He was right the first time, and again now, if only he has the political courage and reliable revenue statistics to see this increase through.

The numbers this time look this way: Gov. Hughes says a wholesale gasoline tax would produce $525 million over the next five years; the increase in the price of gasoline at the pump, depending on how retailers absorbed this increase, could be more than four cents a gallon. Most of the money would be dedicated to highway and bridge projects that were deteriorating before and have been ever since the governor's last call for a gas tax increase. To underscore his born-again fiscal thinking, Mr. Hughes said last week, "I think there's a general recognition that we need to do something," adding that his proposal may have tough going in an election year.

Also on the boards at this hour is a proposal for a modest increase in the tax on heavy trucks, which could yield $18 million a year. That's not big potatoes, but it's sure to draw roars from trucking interests and members of the legislature who are still smarting over the governor's efforts last year to push a bill increasing weight limits for tractor-trailers on state highways.

All political shenanigans aside, these tax increase proposals may go through the General Assembly after all--since most of the state legislators long ago recognized the necessity for action and might have seen it through had there been more leadership on the part of the governor. If there's agreement on one thing, it's that Maryland's roads cannot withstand too many more political detours.