• The Working Group maintains an Executive Committee that has authority to make decisions on all matters other than those reserved to the Working Group. The Chair of the Working Group also serves as chair of the Executive Committee. The Chair calls and presides over Executive Committee meetings. Decisions are made by majority vote with the Chair making a final decision in the event of a tie. The Executive Committee may consider and vote on issues either during a general Working Group meeting or during a separately scheduled Executive Committee meeting. The Chair or members of the Executive Committee will in most cases propose the issues to be decided by the Executive Committee. The Diesel Difference Working Group, individually or collectively, may also request that the Executive Committee consider an issue.

• The Executive Committee's members consist of representatives from: 1) the Philadelphia Department of Public Health, 2) Region III of the United States Environmental Protection Agency, 3) the Pennsylvania Department of Environmental Protection, 4) the Managing Director's Office of the City of Philadelphia, 5) the Delaware Valley Regional Planning Commission, 6) the Clean Air Council, and 7) an organization or a fleet operator representing diesel fleet operators/managers. The States of Delaware and New Jersey may choose to become members of the Working Group and in this case(s), would also become a member(s) of the Executive Committee through representatives from the New Jersey Department of Environmental Protection and/or the Delaware Department of Natural Resources and Environmental Control. In the event that New Jersey joins, Region II of the Environmental Protection Agency would also be invited to join and to become a member of the Executive Committee. Each organization that is a member of the Executive Committee designates one individual as its voting representative. The diesel fleet owner/operator that has a representative serving on the Executive Committee will be chosen from among the diesel fleet owner/operators who are members of the Diesel Difference workgroup. If several diesel fleet owner/operators volunteer to have representatives serve on the Executive Committee, the diesel/fleet owner/operator whose representative serves on the Executive Committee will be chosen by lot. That diesel fleet owner/operator's representative will serve for one year. A diesel fleet owner/operator shall not have a representative on the Executive Committee for consecutive years, unless that fleet owner/operator is the only one that volunteers to serve for the next year.

• Only Working Group members may vote. Votes are taken only when the Chair and a majority of the members of the Working Group's Executive Committee are present. If a participating organization sends several individuals to a meeting, it shall designate only one individual authorized to vote on its behalf. The fleet operator's representative may vote on any issue except one where the Chair believes there is a potential financial or other type of conflict of interest. In this case, the representative will recuse him or herself from the vote. Any participant may make a motion for a vote of the group of which the participant is a member, or may second such motions.

Subcommittees

• The Working Group may establish a subcommittee, by majority vote, when it believes that its formation is necessary to accomplish a task and/or investigate an issue. The Chair of the Working Group appoints the subcommittee members, who may volunteer for such appointment. Subcommittee members elect a sub-committee chair by majority vote. Subcommittees end when they have completed their tasks or investigations, as indicated by the Executive Committee voting to accept the subcommittee's final report and requiring no further action. Five subcommittees currently exist, as follows: 1) non-monetary recognition criteria, 2) organizational structure, 3) mobile source emissions reduction credits, 4) tax credits, and 5) corporate sponsorship.

• Subcommittee chairs are responsible for calling meetings and establishing agendas, preparing and distributing subcommittee meeting notes, providing interim and final reports to the Working Group and its Executive Committee, and for ensuring that subcommittee activities are conducted in accordance with the agreed ground rules for behavior.

Coordinator

• The Chair of the Working Group and its Executive Committee appoints a Coordinator to facilitate the operations of both the Working Group and the Executive Committee. The Chair may delegate to the Coordinator duties such as establishing meeting agendas, preparing and distributing meeting notes, facilitating the creation of clean diesel technology projects, overseeing contracts, and monitoring and reporting progress.