To rebuild America and help the jobless, too

The United States has a great need and a great resource to meet it. New ways are being offered on how to bring them together: the great need for rebuilding the nation's deteriorating physical facilities such as roads and bridges; the great resource of 10 million unemployed Americans looking for a job to do.

The latest suggestion came from the National Urban League convention in Los Angeles. It concentrates on the cities, calculating their cost of rebuilding at to provide the jobs and training to address the problem of unemployment and the problem of rebuilding at the same time. Since the rate of unemployment is particularly high among black Americans, the plan includes such elements as company and community cooperation on creative jobs and training programs reaching to the black unemployed.

Much thought would have to be given to make such a ''universal employment and training system'' work. The $100 billion is obviously not going to come from the federal government in a time of budget cutbacks, though the league estimates the government would have to provide a significant amount. There would have to be a multiplication of the recruiting and training efforts already underway in the private sector. There would have to be consideration of earmarked sources of revenue to underwrite the government's share. A gasoline tax, for example, might be appropriate in view of the major need for road repair.

The immediate virtue of the Urban League's self-styled ''Marshall Plan-like'' proposal is to dramatize the twin goals of restoring the so-called infrastructure and reducing unemployment:

* Infrastructure. The problem reaches far beyond the cities. Everyone is aware of the pothole explosion. Business is concerned about the drawbacks presented by many faltering federal, state, and local facilities. (US Steel, for example, is reported by Business Week to be losing $1.2 million a year in employee time and wasted fuel because of rerouting trucks around a bridge in disrepair.) More than 8,000 miles of the interstate highway system have exceeded their designated life span and are due for rebuilding. Roads outside the system are estimated to require rehabilitation costing more than $500 billion during this decade. Add more than 200,000 bridges, as well as water, sewage, and mass transportation systems that need fixing. Add also the restoration of the natural environment, something already addressed in pending legislation for a modest version of the old CCC to put unemployed young people to work at national parks and monuments.

* Unemployment. There is already a law intended to produce more or less the guaranteed employment results sought by the Urban League. The full-employment legislation of 1978 required the president to set goals to bring down unemployment to 4 percent for persons of 16 and older by 1983. That outcome now seems remote, but the sequence of means prescribed for achieving it still has merit: regular private sector jobs, private sector jobs with federal assistance, conventional public sector jobs, and a ''last-resort government employment reservoir.''

The present administration has minimized government employment by cutting CETA jobs. So far it has not appeared to be doing enough to promote the other forms of employment. President Reagan relies on eventual overall recovery to do the trick - supplying ''real'' jobs. This is a worthy ideal. But in the meantime, as the Urban League and others proclaim, people are hurting. And unemployment itself is a drain on the Treasury both in lost revenue and benefits to jobless workers - as much as $28 billion for each 1 percent rise in unemployment, according to one estimate.

Mr. Reagan's eloquent call for jobs during the campaign ought to be echoed now. He does not have to accept the Urban League plan to take a look at it and - as he so often challenges Congress to do - come up with something better if he doesn't like it.