The MPO can adopt projects in the metropolitan transportation plan and TIP that help to reduce emissions. Examples include: HOV lanes, public transportation investments, signal timing, bicycle lanes, and coordinating land use planning with transportation planning. Other projects that can be implemented including retrofitting, repowering, or scrapping old trucks; supporting idling reduction at truck stops; or encouraging accelerated use of cleaner fuels, especially low sulfur diesel fuel. Appendix B includes a more detailed discussion of options to reduce emissions from on-road motor vehicles.