The District is repairing 30 miles of city streets and five bridges this year--most of the projects are under way this summer--in an $83 million effort to fight roadway decay.

Until last year, the city was repairing an average of 10 miles of streets a year, and increasingly was being referred to as the "pothole capital of the nation" by officials of the American Automobile Association.

In releasing a list of about 140 streets that are being repaired and sections of five major city corridors that are receiving comprehensive improvements, Mayor Marion Barry, who is running for reelection this year, said, "This is the second year of my program to turn around years of neglect of the District's roadways and to improve conditions for drivers and neighborhood residents alike."

In addition to increasing the construction budget from $55 million last year to $83 million this year, the city spent an extra $700,000 last winter from this year's operating budget to make emergency repairs because of the large number of potholes. Barry said the potholes were caused by a lack of roadway maintenance in previous years and last winter's severe weather.

In the city's proposed budget for fiscal 1983, which begins Oct. 1, D.C. officials expect Congress again to approve about $83 million.

City transportation officials say that in the next two years they plan to double funds for replacement of trees along city streets, planting 3,000 trees instead of the 1,500 being planted this year.

The District has about 1,100 miles of streets, 1,600 miles of sidewalks, 300 bridges, 500 small parks and 100,000 trees lining the streets.

The five bridge repair projects under way or about to begin include Chain Bridge, the 14th Street bridge over Maine Avenue, the Franklin Street bridge at 10th Street NE and bridges on New York Avenue and Benning Road.

During fiscal 1983, the city plans repairs to four more bridges including a major reconstruction of the George Mason Memorial Bridge (the 14th Street bridge that carries southbound traffic over the Potomac) and repairs to South Capitol Street Bridge over Oxon Run, the Minnesota Avenue bridge over East Capitol Street and one bridge on Interstate 295 in Anacostia.

The five transportation corridors receiving extensive improvements to roadways, curbs, sidewalks and street-side plantings include Constitution Avenue from Pennsylvania Avenue NW to 19th Street NE; Wheeler Road SE from Alabama Avenue to Southern Avenue; Benning Road SE from East Capitol Street to Southern Avenue; South Dakota Avenue NW from Michigan Avenue to Riggs Road; and Calvert Street NW, from Cleveland Avenue to Columbia Road.