Public support for retaining the 55 mileperhour speed limit as a national law is at a new high, according to a September Gallup Poll. The 55 limit – a reduction from previous speeds – was imposed in 1974 primarily because of the energy shortage. Previous polls had pegged public support at 72-73 percent in 1974, 76 percent in 1977. and 71 percent in WI9, the latter a setback. But this year’s September survey showed a decisive upturn to 80 percent. Three main reasons were given: lower traffic fatalities under the slower speed; Savings in petroleum; And reduced cost of running cars at lower speeds. Gallup recorded solid majorities in each of the geographical regions. including the west where criticism was sharpest. Adults 18 to B appear to be as likely to favor keeping the law as folks more than 30. A plank in the Republican platform favors abolishing the 55 mph ceiling. But the new ” poll shows majorities of Republicans (76 percent) as well as Democrats (85 percent) and Independents (78 percent) indicate ap proval with the law as it is. Statistics on traffic deaths bear out the safety claim. in 1973 55,511 persons died on American highways in a somewhat established pattern. The 55 mph limit took effect in 1974 and that year fatalities dropped to 46,200. The annual toll has inched upward since. but it stays well below pre-IW4 levels, with 48,911 in 1977, 51,500 in 1978, and 50,745 in 1919. As for fuel savings, it’s been estimated that petroleum consumption would increase by a garter million barrels a y if the speed limit were raised. The new poll amotmts to a solid argument for leaving the speed limit at 55. and puts extra pressure on opponents to come up with compelling reasons for a change.