The Government has rejected for now the transport lobby's push for a major change to the Road User Charges system.
The Road Transport Forum says the current Cost Allocation Model, which sets out what diesel vehicles pay in road user charges, is distorted.
The forum says it has ten years of research to prove the amount being paid by heavy vehicles is far too much for the wear they cause.
Transport Minister Steven Joyce says work is being done on the Cost Allocation Model, but he recently told the forum that it shouldn't expect major changes.
He says every road user believes they're paying too much and has research to back it up.