Concern over £1bn M4 relief road options
17 June 2014 Last updated at 21:10 BST
Concerns have been raised over plans for a £1bn M4 relief road to ease traffic congestion around Newport.
All three routes involve a new road to the south but not enough attention has been paid to an alternative solution, said the assembly's environment committee chairman.
Alun Ffred Jones's letter to the transport minister also raises environmental and financial issues.
The Welsh government said the minister would respond in due course.
Paul Martin reports.