Air quality regulators in California are set to consider relaxing some of the state’s tough rules in a meeting set for later this week.

The proposal by the California Air Resources Board would push back deadlines by a few years for small fleets, lightly used trucks and those in rural areas with cleaner air, and offer other adjustments to assist truck owners, according to the Los Angeles Times.

It reports the changes being considered come in response to pressure from small trucking firms and owner-operators, required to install costly diesel particulate filters or upgrade to cleaner models for the first time this year, who have pleaded for more time to comply.

Those opposed to the changes, including the National Resources Defense Council, are urging the board to back away from the proposal to help preserve steps the state has taken to reduce pollution, while some in trucking say the cost of increasing regulations in the state is hurting them. Others in trucking want no delay in the regulations, saying they have spent enormous amounts of money getting ready for compliance.

Read more about it in the Los Angeles Times.