Police have traced the driver of a vehicle suspected of being involved in the motorway collision in which a Polmont teenager died.
The incident took place on the M9 near to Cadgers Brae interchange in Grangemouth late on Friday night.
Michael Easton (13) was found dead by the side of the road around 5.40 a.m. the next day.
Police now believe he had crossed the eastbound carriageway before the collision.
Investigations are continuing and police are keen to trace drivers who were on the M9 between 9.50 p.m. and 10.15 p.m.
They are particularly keen to hear from the driver of a silver Audi car travelling west, which is thought to have been driven by a witness and was not involved in the collision.
Detective Inspector Graeme Hendry said: “We have had a good response from the public and, as a result, we were able to narrow down the timeframe.
“I am appealing to all drivers who were on the motorway between these times to contact us on 101.
“Investigations are continuing into the cause of the collision and Michael’s family have requested privacy during this time.”