Snow Plan in Effect

Cambridge's snow-emergency plan had as first serious test last night, as slushy snow forced the special parking regulations into effect. Traffic Commissioner Robert Rudolph declared an emergency at 10 p.m., prohibiting parking on both sides of main arteries and one side of other streets.

Cars violating the regulation are supposed to be towed away, but a spokesman for the police department last night would say only that such action was possible." On the whole, he declared, the new regulation was "working very nicely."