At GOP convention, political road signs for '84 and beyond say 'Right turn only.'

Republicans have drawn deep fault lines between themselves and the Democrats in the 1984 election race. As the GOP National Convention takes up the Republican Party platform today, the distinctions between the two policy statements are as sharp as they have been in many elections. They include such issues as equal rights for women, nuclear arms control, tax increases, and separation of church and state.

Political platforms are not the stuff of voter excitement. Even politicians tend to pay little attention to them.

''I give it about three days before people forget all about it,'' says Sen. Robert Dole (R) of Kansas. ''Generally things are so broad that everyone can find comfort in it.''

Presidents, moreover, can ignore platforms. Reagan campaign manager Edward Rollins says that parts of the GOP platform will be injected in the campaign, but that President Reagan, while ''comfortable'' with the platform, will run on his record. ''Many things in the platform never become administration policy,'' Mr. Rollins says.

Still, the platform is a kind of barometer of the state of the party at the moment and of where its controlling voices would like to take the country. Voters will want to know that this year the conservative wing of the party dominated the platform process, leaving moderate Republicans disappointed.

In fact, many of its provisions, especially on social issues, do not reflect the Republican rank and file - or the views of the delegates to the convention. A survey by the Los Angeles Times found that the delegates, by a majority of 3 to 2, oppose a constitutional ban on abortion. A majority also support a nuclear freeze.

Moreover, while incumbent presidents usually dictate their party's platform, the Reagan administration lost some major points as the conservatives pushed through a no-tax-increase plank, a pledge to work for reduction in taxes on interest income, and a sharp criticism of the Federal Reserve Board.

Supply-side conservatives are enthusiastic. ''The 1984 platform is bolder, more entrepreneurial, more radical,'' says Rep. Jack Kemp (R) of New York, one of the prime movers behind the platform's drafting. ''This is the most radical platform in the history of either party.''

Conservatives on the religious right are no less pleased. The Rev. Jerry Falwell, head of the Moral Majority, has strongly endorsed the platform.

Moderates won some concessions on environmental policy. But they tried unsuccessfully to modify the platform with language supporting the Equal Rights Amendment and funding for abortions in the case of rape or incest. They also unsuccessfully sought to delete a plank urging judicial appointments of anti-abortion advocates and to include an amendment that would discourage legislative efforts to tamper with the powers of the judiciary.

''The product of the platform committee is being lauded by Moral Majority and the radical right, but it is not a document for all Republicans,'' says Mary Lousie Smith, a delegate from Iowa and former chairwoman of the Republican National Committee.

''As written, it invites dissent, guarantees disregard, and ensures more discussion of the concerns it so blatantly ignores.''

These concerns of the moderates could be opened on the convention floor. But the rules for doing this are such that most observers expect the platform to be adopted without floor battles.

On foreign policy, the GOP platform is hard-line compared with its Democratic counterpart, pledging support for the anti-Sandinista rebels in Nicaragua, for example.

While the GOP drafters dropped the 1980 call for ''military superiority over the Soviet Union,'' the new platform calls for ''technical'' and ''qualitative'' superiority - which the conservative right wing interprets to mean military superiority.

Following are major provisions of the GOP platform, contrasted with its Democratic counterpart:

Federal income taxes. Republican: ''We therefore oppose any attempts to increase taxes, which would harm the recovery and reverse the trend to restoring control of the economy.'' Democratic: ''We will cap the effect of the Reagan tax cuts for wealthy Americans and enhance the progressivity of our own personal income tax code. ... We will partially defer indexation. ... There must a return to a far tax on corporate income.''

Republican: ''We oppose withholding on dividend and interest income.'' Democratic: No provision.

Republican: ''We therefore support tax reform that will lead to a fair and simple tax system, and believe a modified flat tax - with specific exemptions for such itmes as mortgage interest - is a promising approach.'' Democratic: ''We will cap the effect of the Reagan tax cuts for wealthy Americans and enhance the progressivity of our personal income tax code.''

Deficits. Republican: ''We favor reducing deficits by continuing and expanding the strong economic recovery ... and by eliminating wasteful and unnecessary government spending.'' Democratic: ''The Democratic Party is pledged to reducing those intolerable deficits. We will reassess defense expenditures; create a tax system that is both adequate and fair; control skyrocketing health costs without sacrificing quality of care; and eliminate other unnecessary expenditures.''

School prayer. Republican: ''Mindful of our religious diversity, we reaffirm our commitment to the freedoms of religion and speech guaranteed by the Constitution of the United States and firmly support the rights of students to openly practice the same, including the right to engage in voluntary prayer in the schools.'' Democratic: ''The Democratic Party affirms its supports of the principles of religious liberty, religious tolerance and church/state separation , and of the Supreme Court decisions forbidding violations of those principles. We pledge to resist all efforts to weaken those decisions.''

Women's rights. Republican: ''The Republican Party has an historic commitment to equal rights for women. ... As a party, we demand that there be no detriment to women's progress or inhibition of women's rights to full opportunity and advancement within this society. Democratic: ''A top priority of a Democratic administration will be ratification of the unamended Equal Rights Amendment.''

Abortion. Republican: ''The unborn child has a fundamental individual right to life which cannot be infringed. We therefore reaffirm our support for a human life amendment to the Constitution.'' Democratic: ''We also recognize the belief of many Americans that a woman has a right to choose whether and when to have a child. The Democratic Party supports the 1973 Supreme Court decision on abortion rights as the law of the land and opposes any constitutional amendment to restrict or overturn the decision.''

Environmental Protection Agency. Republican: No mention of the agency. ''We will be responsible to future generations, but at the same time, we must remember that quality of life means more than protection and preservation. (It) means development as much as it does protection.'' Democratic: ''The Environmental Protection Agency should receive a budget that exceeds in real dollars the agency's purchasing power when President Reagan took office.''

Nuclear power plants. Republican: ''We will work to eliminate unnecessary regulatory procedures so that nuclear plants can be brought on line quickly, efficiently and safely.'' Democratic: ''The Democratic Party strongly opposes the Reagan Administration's policy of aggressively promoting and further subsidizing nuclear power.''

Gun control. Republican: ''Republicans will continue to defend the constitutional right to keep and bear arms.'' Democratic: ''We support tough restraints on the manufacture, transportation, and sale of snub-nosed handguns, which have no legitimate sporting use and are used in a high proportion of violent crimes.''