Air Quality Planning for Transportation Officials

Transportation Control Measures

Of the control strategies States may choose to implement, some may be on-road mobile source measures to reduce vehicle use or change traffic flow or congestion conditions. These measures are known as transportation control measures (TCMs). A TCM is any measure that is specifically identified in the SIP for the purpose of reducing emissions or concentrations of air pollutants from transportation sources.

The SIP must provide for the implementation and enforcement of TCMs. TCMs should be developed jointly by transportation and air agencies as part of the transportation planning process, and incorporated into the SIP. In addition, many transportation plans and TIPs include TCM-like projects such as transit investments or HOV lanes, which are not included in the SIP. These measures can help improve air quality but are not considered legally enforceable commitments unless they are identified as TCMs in the SIP.

TCMS that are identified in the CAA include:

• Programs for improved public transit

• Restriction of certain roads or lanes to, or construction of such roads or lanes for use by, passenger buses or high-occupancy vehicles

• Employer-based transportation management plans, including incentives

• Trip-reduction ordinances

• Traffic flow improvement programs that achieve emission reductions

• Fringe and transportation corridor parking facilities serving multiple-occupancy vehicle programs or transit service

• Programs to limit or restrict vehicle use in downtown areas or other areas of emission concentration particularly during periods of peak use

• Programs for the provision of all forms of high-occupancy, shared-ride services

• Programs to limit portions of road surfaces or certain sections of the metropolitan area to the use of non-motorized vehicles or pedestrian use, both as to time and place

• Programs for secure bicycle storage facilities and other facilities, including bicycle lanes, for the convenience and protection of bicyclists, in both public and private areas

• Programs to control extended idling of vehicles

• Reducing emissions from extreme cold-start conditions

• Employer-sponsored programs to permit flexible work schedules

• Programs and ordinances to facilitate non-automobile travel, provision and utilization of mass transit, and to generally reduce the need for single-occupancy travel, as part of transportation planning and development efforts of a locality, including programs and ordinances applicable to new shopping centers, special events, and other centers of vehicle activity

• Programs for new construction and major reconstruction of paths, tracks or areas solely for the use by pedestrian or other non-motorized means of transportation when economically feasible and in the public interest

• Programs to encourage removal of pre-1980 vehicles