SB 1087 revises California’s transportation planning process by requiring, starting with RTPs adopted on or after January 1, 2027, that every second regional transportation plan (i.e., every eight years) include a new sustainable communities strategy, with an implementation report required in intervening years; shifts responsibility for reviewing sustainable communities strategies and alternative planning strategies from the State Air Resources Board to the California Transportation Commission, with deemed approval if the Commission misses specified deadlines; updates greenhouse gas emissions targets for the 2035 on-road transportation sector based on fleet efficiency and reduced vehicle miles traveled, eliminates the state board’s authority to revise targets every four years, and requires enhanced public participation; exempts the preparation and adoption of RTPs, SCSs, and APSs from CEQA if enhanced public outreach is conducted; requires that $25,000,000 in Road Maintenance and Rehabilitation Program local planning grants be allocated based on population share; and aligns the State Highway Operation and Protection Program, Trade Corridor Enhancement Program, and Solutions for Congested Corridors Program with regional transportation plan timing, phasing, and scope, including requiring GHG emission reductions for projects under an alternative planning strategy.