At Arriva he will report to group MD of corporate affairs Steve Clayton and replaces Julian Evans, who left early this year.
Ex-Jarvis group communications director Jonathan Haslam will continue to act as Evans's interim replacement until Craven starts.
Arriva – which provides passenger transport services in seven Continental countries as well as the UK – employs more than 30,000 staff.
It retains Tulchan Communications for financial PR while Kate Read remains head of media relations. It also employs three corporate comms managers and is planning to bring in a CSR manager.
Prior to BT, for which he held various roles since 1998, Craven worked for Cambridge-based telecoms firm Ionica.