Between 40 and 60 percent of Washington motorists drive around town on any given day without car insurance, according to a report released this week by the Washington-based consumer group Automobile Owner's Action Council.

The report adds that there is reason to believe uninsured motorists are more accident-prone than insured drivers.

But the days of the uninsured motorist may be over, if no-fault automobile insurance becomes mandatory in the District.

Hearings today on proposals to introduce some form of mandatory automobile insurance will set the stage for one of the liveliest legislative debates expected in the city this year.

There has been no official estimate on the cost of no-fault premiums. When introducing a proposal on no-fault automobile insurance last October, Council Chairman Arrington Dixon said the coverage would cost each District motorist $127 a year, but offered no comparison with the current cost of a basic insurance package.

But August P. Alegi -- assistant vice president of the Government Employees Insurance Co., the city's biggest insurer and one known for relatively low premium costs -- said no-fault coverage would cost $82 a year, compared with an average of $145 for a basic insurance package today. Like other advocates of no-fault, Alegi said the reduction is made possible by lower administrative costs.

Motorists will have to shoulder premium costs for no-fault insurance in addition to coverage protecting against property damage and other accident-related costs.

The Dixon bill would require insurance companies to set up a pooling arrangement offering policies to high-risk drivers.

Witnesses testifying today represent a broad spectrum of views ranging from the insurance industry -- which generally supports the proposal -- to the legal profession -- which opposes it. The general public may also make its views known.

All the proposals being considered would require automobile owners in the District to carry liability insurance, and make it a crime to drive without this coverage. It is estimated that the owners of 114,000 cars -- four out of every 10 registered in the city -- currently carry no insurance. -

In addition to assuring compensation to accident victims without the need to fix blame, the no-fault system would help hold down rising premium rates or even reduce them, supporters of the system say.

But trial lawyers, who have fought such measures whenever proposed in state legislatures and Congress, say the no-fault proposal would sharply curtail the existing right of victims to sue for damages.

In considering the no-fault proposal, the D.C. council will be acting for the nation's capital as a state legislature would. Any bill enacted, however, would be subject to review and possible veto by Congress, which in 1978 rejected national no-fault legislation.

The D.C. council has four bills pending, but today's testimony is expected to center on two of them:

The first was introduced by Dixon and cosponsored by five others on the 13-member council. It would set up a comprehensive no-fault system and require everyone to be insured.

The second was introduced by Wilhelmina J. Rolark (D-Ward 8), the committee chairman, who will preside at the hearings. It would require every car owner in the city to carry liability and collision coverage.

The other bills were introduced by Betty Ann Kane (D-At Large) and by Nadine P. Winter (D-Ward 6).

Kane said her bill was modeled after the highly successful Michigan no-fault law, and would provide more generous benefits than the Dixon bill. She said she would support the latter if it proved more politically feasible.

Dixon said his bill was drafted with help from the Committee for Consumers No-Fault, a national coalition of insurance companies, consumer groups, unions, vehicle fleet owners and car rental firms.

The measure would permit a person injured in an accident to submit a substantiated claim for up to $124,000 in expenses and lost wages without having to prove who was at fault. The claim would be paid by the insurance company carrying the policy on the car in which the injured person was riding or -- if the injured party is a pedestrian -- on the car involved.

Under typical insurance practice now, a motorist making a claim must demonstrate that the accident was the fault of the other driver or of circumstances beyond the motorist's control. Generally, such claims are paid by the company that insures the person found to be at fault.

With few exceptions, lawsuits would not be permitted by injured persons attempting to recover damages unless they exceed $124,000, plus $1,000 in death benefits.

Kane said her bill would not set any limit on payments. She said both bills allow lawsuits in cases involving permanent disability or disfigurement.

Nationally, no-fault coverage accompanied by restrictions against lawsuits has been fought by the Association of Trial Lawyers of America, whose members earn part of their livelihoods trying such cases.

Charles C. Parsons, president of the association's local affiliate, the Association of Plaintiffs' Trial Lawyers of Metropolitan Washington, said a spokesman for his group will testify against the no-fault bills.

He said the Dixon measure is "an insurance industry bill . . . highly disadvantageous to the general public and highly advantageous to the insurance industry."

Saying that auto injury cases represent a fraction of his own practice, Parsons insisted that "I don't see myself as an ogre" as trial lawyers often are painted in the media.

"We will show in our testimony that the only way to deal with (auto insurance) is on a case-by-case basis," Parsons said. He said the only proposal the trial lawyers could work with is the Rolark compulsory-insurance bill.

More than 30 witnesses are scheduled to testify before the City Council's Public Services and Consumer Affairs Committee at sessions scheduled for 10 a.m. and 5 p.m. Others interested in testifying may sign up at the hearings.