Despite a growing perception that the 55-m.p.h national speed limit is widely ignored, most Americans favor retaining the law, according to the Gallup Poll. But public support was found to be the lowest since the law was enacted in 1974. In the mid-June survey, 66% favor keeping the national speed limit at 55, while 32% would like to see it repealed. Support for the law grew from 73% after the Arab oil embargo in 1973 to a peak of 81% in 1980. The latest survey showed that most Americans support the statute because they believe it saves lives.