A new video has emerged on social media of a car being driven on the wrong side of the road outside the RAF base near where 19-year-old Harry Dunn died.
Mr Dunn was killed after a crash by RAF Croughton in Northamptonshire which led to suspect Anne Sacoolas leaving the UK under diplomatic immunity.
The footage appears to have been recorded on Thursday. Another car was recorded being driven on the wrong side of the road near the base last month.
Police said they would investigate.
Dunn family spokesman Radd Seiger said the emergence of the latest video near RAF Croughton was “shocking but not a surprise”.
The crash that killed Mr Dunn happened on 27 August outside the RAF base where Mrs Sacoolas’s husband Jonathan worked as a US intelligence officer.
Mrs Sacoolas, 42, is to be charged with causing death by dangerous driving.
In January, US Secretary of State Mike Pompeo rejected the UK’s request for her extradition.
Northamptonshire Police Chief Constable Nick Adderley met the US air base’s commander on Thursday to discuss safety.
He said his meeting with Colonel Bridget McNamara was “encouraging”.
A joint statement released by the police and the colonel said Ms McNamara “provided a detailed brief of all the proactive measures that the base continues to do to help those living on the base adjust to UK driving standards”.
“It was clear from the meeting that the base already had a significant number of measures in place in ensuring driver safety,” Mr Adderley said.
“The base and the force have continued to work together.”
“Additional provisions” are to be introduced and both parties “are doing all that they can to prevent any future harm on the roads in and around the site”, he said.
Colonel McNamara said Northamptonshire Police had been a “steadfast partner of our base” and she looked forward to its continued relationships.
Mr Seiger said the family was “shocked” at the news of the meeting, and said Mr Dunn’s family “should have been there”.
He said Northamptonshire Police and the US Air Force “fail to acknowledge that there is a problem”.
“As evidenced by further video today, a further tragedy is inevitable,” he added.