The charging systems presently being used in toll facilities impose discomfort and inconvenience to patrons, in terms of delay and stops. This report presents an analytical method to estimate delay and stops in toll plazas. These variables are then utilized to evaluate user costs and toxic gases emitted in toll plazas. A large amount of information on highway user costs was collected and synthesized to be incorporated in this economic evaluation. Recommendations on the amount of toll that should be charged to take into account user costs induced by toll plazas are given in this report. / Master of Science