When the biggest question about an impending election is not whom you will vote for but whether you will be able to vote, time has come to change the system.

It is estimated that 50,000 voters in the District of Columbia who tried to get properly registered may have trouble casting their ballots Sept. 14--through no fault of their own. Their registration records are missing, inaccurate or incomplete.

Since last November, we have heard many proposed solutions to the problem, including data processing improvements, re-registration, the posting of registration lists in libraries and the wholesale removal of the board of elections and ethics. None of these solutions is dramatic or fundamental enough to actually convince the average District voter that he or she will actually be able to vote. A voter doubting that chance to vote is just the one who may stay away from the polls on Election Day.

Voting is a franchise so fundamental to the fabric of American life that we take it for granted. Registering to vote must be made as simple as possible while still maintaining the integrity of the system.

There is a way of accomplishing this that is stunning in its simplicity and unequaled in its effectiveness: Election Day registration. It is a system that was seriously considered after extensive hearings by the D.C. Council's government operations committee, which I chaired, in 1975. The committee held back its recommendation because it would have meant too many changes in the elections system so soon after home rule. But it was a good idea then, and it is an excellent idea now.

Election Day voter registration has been used successfully in Maine and Minnesota for nearly a decade. Under the system, a voter may register on Election Day after presenting a valid driver's license or other substantial proof of residence. A person without such identification could be sworn for by a bona- fide voter in the precinct. Those who appear in this manner would then be considered registered voters and would receive non-forwardable verification slips, as under our current system.

This registration could be made administratively simple by hiring additional workers to handle the influx of voters on Election Day and by separating lines at precincts so those who are already registered would not have to wait in line with those registering for the first time. Also, it might be possible to limit the number of polling places where a person may register on Election Day.

Some critics will raise the possibility of fraud as an issue to be considered. In the states where same-day registration has been tried, fraud has been virtually nonexistent. There have been no cases brought in Maine and only three in Minnesota for voters who had voted fraudulently in the wrong precinct. There is no reason to think that voters in the District are any less ethical than those in Maine or Minnesota. Besides, penalties for violations of the election laws are stiff in the District--five years in jail or a $10,000 fine. These alone should dissuade anyone who considers tampering with the system.

When you consider the fact that same-day registration boosted the number of voters in Minnesota by 22 percent the first time it was used, arguments against the system do not appear convincing. Thousands of people voted who had not voted before. And that put Minnesota's voting participation rate at 12 percent above the national average.

Voting is the most fundamental right of our democracy. Let us knock down barriers to the ballot box--and to the franchise that we worked so hard to attain.