This bill introduces a new section to RSA 265, specifically section 75-a, which prohibits the operation of diesel-powered motor vehicles with a manufacturer's gross vehicle weight rating under 18,000 pounds if they emit visible smoke on public ways or parking areas due to alterations in the exhaust or emission control systems, commonly referred to as "rolling coal." Violators of this provision will be subject to penalties classified as a violation. The bill is set to take effect on January 1, 2026.

In terms of fiscal impact, the bill is expected to have indeterminable effects on state and local expenditures, particularly concerning the judicial and correctional systems due to the potential increase in prosecution and enforcement costs associated with the new violation. However, there are no anticipated changes in revenue for the state or counties as a result of this legislation. The bill aims to address environmental concerns related to diesel emissions while establishing a legal framework for enforcement.