Striking Teamsters Union truck drivers yesterday overwhelmingly ratified a new contract with the Safeway supermarket chain that will raise their salaries from $14 to $15.70 an hour over the three-year life of the pact.

The truckers, members of Teamsters Local 639, had been on strike since Sunday in a dispute that centered on whether Safeway could impose a new work rule requiring drivers to unhitch their trailers after delivering food, giving the company the right to unload the trucks at its convenience using workers paid less than the drivers.

The union and Safeway compromised on the dispute and the contract was ratified, 198 to 5. The union ordered the drivers to report to their normal shift, starting at 6 p.m. last night.

The drivers, who deliver goods to 151 stores from southern Pennsylvania to Fredericksburg, Va., will now be required to drop their trailers for unloading by other workers at Safeway stores within 35 miles of the food chain's Landover distribution center, provided that all 210 current drivers are still working.

If any drivers are laid off, Safeway agreed to let those remaining unload their trucks. In addition, the Teamsters and Safeway agreed that 12 drivers currently laid off will replace any of the 210 in the protected list if they retire, die or are fired.

"Right now, there will be dropped trucks," said John Steger, Local 639's vice president and chief union negotiator in the contract talks. But he praised the compromise for the job security it provided.

The union and Safeway also agreed to binding arbitration on another dispute, whether a year-old store in Fredericksburg should receive deliveries from Landover or from another center in Richmond, where drivers are paid less.