California environmental regulators were expected late last week to make public their final slate of proposed amendments designed to help motor carriers ease the financial pain of complying with the state’s tough heavy-duty truck greenhouse gas emissions reduction and retrofitting regulations.

A slate of proposed amendments to California’s tough heavy truck diesel emissions reduction regulation would save the trucking industry more than $3 billion in retrofits and engine replacements and delay some compliance requirements by a year or more, according to a report by the state’s environmental regulatory staff.

Lawyers for American Trucking Associations have filed a petition asking that all 13 federal appeals court judges with the District of Columbia Circuit reconsider a three-judge panel’s decision that let California’s “reefer retrofit” rule stand.