Prince George's County officials said this week that they did not formally oppose the federal government's proposal to convert highway signs to metric measurements, as reported June 30 in the Virginia Weekly. John C. Rice, chief of the Prince George's traffic operations division, said he was mistaken when he told a reporter that a letter he drafted for the signature of his boss. Donald R. Dunker, director of public works and transportation, had been signed and sent. Dunker said he neither opposed metric conversion in principle nor disagreed with the staff recommendation, which opposed the highway sign plan as too costly and too soon. "The county had not really taken a position," Dunker said. "I thought the staff position got into some areas such as financing that should be made by the county executive - We are not opposed to the metric system, but we do have problems with the timing and the financing (of the highway agency proposal.)"

Confronted with objections from local and state governments including the State of Virginia, the Federal Highway Administration has abandoned a plan which would have required that all highway signs use metric measurements by late 1984.

The action probably will lead other federal agencies to "stop and think" before they propose similar metric conversion plans, according to Richard Reilly, public affairs officer for the highway agency. He said the Metric Conversion Act of 1975 established metric conversion only as voluntary national policy, not binding law.

The highway agency's proposal called for converting all speed limit signs to metric measure by the end of 1979, and all other regulatory and advisory signs by late 1982. It was killed because of objections based on both cost and safety.

Earl Johnson, a Federal Trade Commission attorney who is a memeber of an interagency committee studying metric conversion, suggested that the highway agency "took people by surprise" before they were accustomed to using kilometer speedometers and meausrements.

"You've got a study in human nature," he said. "We've got a long period (of metric conversion) ahead of us, but it's going to come by bits and spells." Johnson noted that most metric conversions will require cooperation between government and private industry.

State highway officials in Virginia found the plan particularly troublesome; their objections were outlined in a letter by J. P. Mills Jr., state traffic and safety engineer, to Transportation Secretary Brock Adams. The letter was one of the approximately 5,000 negative responses that helped kill the federal plan.

The conversion would have forced some changes in speed limits, highway sign formats and automobile equipment - for example, the 55 miles per hour speed limit would have become 90 kilometers per hour, which works out to about 56 1/4 miles per hour.

Also, metric speed limits on signs would have been followed by the designation "km," standing for kilometers-per-hour. Owners of autos more than two years old, which do not have kilometers-per-hour markings on their speedometers, would have been required to obtain a paste-over kilometer scale for the speedometer.

Virginia officials estimated in 1974 that metric conversion would cost the state highway department $19 million, of which $17 million would be for new highway signs. The state would be responsbile for all signs on interstate highways and state primary and secondary highways.

Leslie Dawson, assistant state traffic and safely engineer, said that in addition to the cost, his department was borthered by the federal plan to convert speed limit signs immediately. He said it would be safer to convert guide-type signs first, and only change the regulatory speed limit signs after motorists have become familiar with metric measurements on the road.