A separately organized city planning commission is usually the best agency for assuming the general responsibility for preparing the plan and to aid the city government and private individuals in carrying out its essential feature. Such a commission usually consists of from 5 to 11 members. It may include the mayor, the city engineer, a representative of the city council or similar body, and prominent citizens serving without pay. The citizen members should always be in a majority. It should be authorized by the city council to expend funds for preparing a plan, and to call on all municipal officials, including the city engineer, the city attorney, and others, for advice and data. The city council, in turn, ordinarily derives its power to grant such authority from an enabling act passed by the state legislature. Such acts are already in effect in many states, and a standard act with full notes to explain its provisions has been prepared by the Department of Commerce advisory committee on city planning and zoning, to serve as a guide to those preparing such legislation.

Where such authority has not been granted, unofficial commissions, sometimes appointed by the mayor, or sometimes representing unofficial civic bodies, may be organized, and often accomplish a great deal, particularly if they succeed in raising private funds for preparing a plan. Such a plan may be followed in many features by the city government.

Practical results are much more readily attained when the commission has official advisory powers.

The official city planning commission, however, should not be charged with executive functions, such as the administration of the park system or some of the usual construction or administrative functions of the city. Past experience indicates that such duties are better left in the hands of regular executive departments and administrative boards.

Since the city planning commission's final responsibility is to see that a good city plan is carried out, one of its functions is to determine how the city's financial resources and expenditures may best provide for its planning needs.