The long lines at the gas pumps couldn't have come at a better time for H. R. 3951, the biggest Metro construction bill to come before Congress since 1971.

The House votes today on that bill, which provides $1.7 billion in federal funds essential for completion of the Metro rail system. In the last few months, a sophisticated lobbying campaign has transferred what some have criticized as a pork barrel project for the Washington area into something hailed as significant energy legislation that could served as a model for the nation.

It could not have worked out better if the sponsors, Reps. Fortney H. (Pete) Stark Jr. (D-Cal.) and Herbert E. Harris II (D-Va.) had planned it that way.

Even before the energy problem hit, the lobbying campaign was being organized by Stark, Harris, House District Committee Chairman Ronald V. Dellums (D-Cal.) and other Washington area members of the House.

The lobbying effort included:

The case of "Whip lists" in which uncommitted members were contacted by the most active supporters of the bill. Del. Walter E. Fauntroy (D-D.C.), for example, put the arm on the Black Caucus; Rep. Michael D. Barnes (D-Md.) hosted a breakfast for his fellow freshmen with Metro general manager Richard S. Page; Rep. Gladys N. Spellman (D-Md.) telephoned members of the Post Office and Civil Service Commission from her bed at Bethesda Naval Hospital; Rep. Joseph D. Fisher (D-Va.) buttonholed colleagues on the Ways and Means Committee.

Maps. Metro general manager Page sent a map of the Metro system to every member of Congress; Harris sent a special map to House members showing how the travelling between the Capitol and National Airport would be reduced to 13 minutes upon completion of the system.

Outside help. Influential members of the Federal City Council and the Metropolitan Washington Board of Trade made personal contacts with individual members. For example, former Pennsylvania Gov. Raymond P. Shafer, now a partner in a Washington architectural firm, reportedly converted five members of the Pennsylvania delegation.

Briefings and receptions. A dozen meetings were held in the last month for members of Congress and their aides. The most successful concentrated on showing Hill staffers who live here year-round when the completed system would reach their neighborhoods.

Paper blitz. In the last few days Governors Harry E. Hughes of Maryland and John N. Dalton of Virginia sent telegrams to their respective House delegations; Oliver T. Carr, president of the city's Board of Trade, sent a letter to all 435 House members; and Hughes, Dalton and D.C. Mayor Marion S. Barry issued a joint statement of support. Earlier, House members got a letter from the American Public Transit Association and reprints of a favorable article in Civil Engineering magazine.

Inside stuff. District Committee legislation goes to the House floor on second and fourth Mondays each month. But July 9 (the second Monday) was not a good time to mount a last-minute offensive because it was the day after Congress returned from its Fourth of July recess. So last month, Dellums got the date changed to July 16. Rep. Robert E. Bauman blocked Dellum's initial request for the needed unanimous consent, but withdrew his objection the next day, after Dellums and Harris cornered him in the cloakroom.

Today's vote is the second major money hurdle for the Metro system in less than a week.

Last Wednesday, Transportation Sec. Brock Adams said he would release millions of dollars of long-delayed Metro construction funds essential to completion of the 101-mile system.

That decision involved about $1.2 billion of available federal money that was gained when several urban freeway projects were canceled. Today's vote in the House involves an additional $1.7 billion necessary to complete the construction project.

In addition to authorizing the $1.7 billion as the federal share of the $2.125 billion needed to complete the 101-mile system, the bill authorizes a $197.7 million federal subsidy toward operating deficits through 1988.It also establishes a two-thirds federal, one-third local formula for retiring the original construction bonds, which were sold under the mistaken assumption that the subway would produce operating profits from which they could be retired.

The first Stark-Harris money would not be available until the 1982 fiscal year. It would allow construction of Metro to continue uninterrupted toward a 1989 completion target. Federal construction money currently comes from the $1.2 billion in interstate highway transfer funds, but that money runs out in 1983.

The last of that money was released by Adams last week. It had been held up by the U.S. government until Metro agreed to speed up construction of the Metro line through the Anacostia section of the District of Columbia.

The last big Metro construction bill came before Congress in 1971. Because 225, or more than half, of the present members were not in Congress then, including Stark and Harris, backers have concentration on "educating" the newcomers about Metro's history. Helping in that effort were the 92 members, called "the fathers of Metro," who voted for the original appropriation eight years ago.

The biggest obstacle to passage, supporters concede, is the price tag. Some members "may perceive this as a cheap way to impress the folks back home that they have saved them $2 billion" by voting against it, Harris said.

One lobbying technique that apparently is paying off involved members from cities that have rapid rail systems, such as New York, Chicago, Boston, Philadelphia and Cleveland. If the Metro bill fails, these members warned, the Washington transit system will be competing against their local subways for funds appropriated for the Urban Mass Transit Administration. That "reverse spin" approach has been helped by the strong support of Dellums and Stark, who come from Oakland, which is part of the Bay Area Rapid Transit system.

The bill stipulates that no federal money can be released until the U.S. Transportation secretary "has determined that local participating governments have provided for a stable and reliable source of revenue" to meet matching requirements for operating costs and the localities' one-third share of payments for principal and interest on bonds.

Harris said those words are aimed at the Virginia General Assembly and Gov. Dalton. In the past, they have rejected proposals by Northern Virginia cities and counties for a special taxing authority to finance their share of Metro.

Dalton's press secretary, Paul Edwards, said the governor does not think that his endorsement of the bill means Virginia has to do anything differently.

The energy crisis has permitted boosters of the bill to advertise it as "much more than just mass transit legislation." That's how Hugh Calkin of the District Committee staff described H.R. 3951 to 20 staffers who had attended a briefing Thursday after Dellums penned hand-written notes to their bosses, all of whom are first-year members.