Nine Northeast states and the District of Columbia will plan a new program to price and reduce carbon emissions from the transportation sector.

It could mimic the Regional Greenhouse Gas Initiative which studies show has been successful in cutting emissions and boosting regional economies.

Passenger vehicles and other forms of transit are the country’s biggest sources of the carbon emissions that drive climate change.

Within the new agreement the states will work to devise a system that would limit and price transportation emissions, and use the resulting revenues to make their transportation systems more resilient.

The states behind the transportation initiative include all New England states, with the exception of Maine and New Hampshire.

“We should be at the table working on solutions with our neighbors and not waiting for things to happen to us,” said Jim O’Brien, of the New Hampshire Nature Conservancy.

But O’Brien said the region’s transportation system is already so interconnected that the state will be affected regardless. He added that fluctuations in the costs associated with transportation may end up pushing New Hampshire towards implementing the plan.

“As we’ve seen with the electric sector, a regional approach on reducing transportation emissions seems like the best way forward – especially at (an) economy-wide way.”

New Hampshire officials say they’ll still participate as the plan is developed. Officials in Maine did not immediately offer a comment. When the plan is finished, each state will decide whether to implement it.