A real-time frontage road progression analysis and control strategy

Urban freeways frequently experience congestion due to normal peak-hour demands exceeding capacity and due to freeway incidents. It is proposed that, at lest during these conditions, the adjacent frontage roads should be operated as major arterials to provide additional freeway capacity. A real-time traffic-responsive frontage road progression analysis and control strategy that could be used in operating the frontage roads as a major traffic-carrying facility is presented. Previous computer control applications and future implementation of the strategy are discussed. The frontage roads are analyzed for progression as if the continuous, one-way frontage roads and diamond interchanges were combined to form a major two-way signalized arterial. To maximize frontage road progression, each interchange is assumed to operate on either a 3-phase or a 4-phase signal sequence. The progression optimization algorithm selects the phase sequence yielding the maximum progression. The traffic-responsive strategy using the 3- and 4-0hase signal sequences is also described.