A woman was seriously hurt but stable while a man is in hospital with non-life threatening injuries.
The motorway is closed at junction 22 with the M77 slip road also shut.
Joshua Kerr's family said he was 'the perfect person and we will forever love him'.
The single-vehicle smash happened on the A85 near to Crieff Golf Club at around 9am on Tuesday.
The three-vehicle collision happened on the A96 in Moray on Tuesday morning.
The collision happened on the A912 Bridge of Earn to Aberargie road at around 6.30am on Friday.