Guidelines are presented to assist transportation agencies select a sign support system. Three major elements are addressed in the guidelines: safety, design, and economics. An economic analysis procedure was formulated whereby the present worth of initial and annual costs of a given support system can be computed and compared with costs of other systems. The procedure was used in an example to analyze the relative costs of available support systems for small sign installations. A limited sensitivity analysis was also performed to evaluate the influence of input parameters on costs.