LONDON — The British police will offer free driver training to employees at an air base that hosts a United States Air Force communication station, after two incidents threatened a repeat of a crash that killed a British teenager and prompted a monthslong diplomatic tug of war between Britain and the United States.

The teenager, Harry Dunn, 19, died in August when his motorcycle collided with a car being driven on the wrong side of the road by an American, Anne Sacoolas, whose husband, also an American, then worked at the base, R.A.F. Croughton.

Ms. Sacoolas left Britain shortly after the crash under a claim of diplomatic immunity, and the United States rejected an official British request to extradite her on a charge of causing death by dangerous driving, despite emotional appeals from Mr. Dunn’s parents, who even met with President Trump.

[Update: U.S. refuses extradition in fatal crash, prompting anger in the U.K.]

Last Friday, another car driving on the wrong side of the road almost collided with another vehicle near the base. That prompted the chief constable of the Northamptonshire Police, which is responsible for the area, to call an urgent meeting with the base commander.