States having major ticket-system toll operations in the US include Florida, Indiana, Kansas, Massachusetts, New Jersey, New York, Ohio, Oklahoma, and Pennsylvania. These toll facilities were all built as ticket-system roads between the 1940s and 1960s. However, because of traffic and operations challenges, no new toll roads in the US have been built with a ticket system since then. Most operators have converted some portions of their facilities from the ticket-system to the barrier system. Toll road sections with lower traffic volumes and large distances between interchanges still function acceptably well as ticket-system operations. The only US roads still operating ticket-system toll collection in major metropolitan areas are the New Jersey and Pennsylvania Turnpikes.
All toll collection points on ticket system toll roads are either at the system end-points, or at every interchange between those endpoints. Every vehicular movement on the system must pass through an entry toll lane and an exit toll lane. Trumpet interchange configurations (Exhibit 2-1) were used in order to bring all interchange traffic to a single point to minimize plaza and building construction, and minimize the cost and complexity of cash-handling operations. Entry lanes can be operated in either an attended or an unattended fashion using ticket-issuing machines. Because the toll amount varies with each vehicle, automation of cash collection was not possible, and all “exit” lanes were built as attended lanes.
As a result of all exit lanes being attended, and the toll amount is varying from vehicle to vehicle, ticket-system exit lanes with substantial commercial traffic process traffic at a very slow rate, often in the range of 180 to 240 vehicles per hour (vph). Ticket system entry lanes, whether attended or unattended, process vehicles more quickly and have similar performance to barrier plazas, with throughputs in car-only lanes up to 600 vph.
Location Requirements for Personnel Support
Ticket system exit lanes must be staffed, so all plazas on a ticket-system road require buildings and infrastructure to support attended operations, such as personnel support, parking, cash handling security features, material and equipment storage, utilities, back-up emergency generators, and other support features. Therefore, all the ticket-system access points provide positive access control, and the attendant ability to close off or meter access when desired, such as during dangerous weather conditions. The building, infrastructure, storage, and parking all limit the space available for plaza pavement, particularly with respect to sight distances, acceleration/deceleration lengths, room for weaving, etc.
Plaza Locations and Geometric Limitations
Trumpet interchange ramps provide short tangent sections on which to locate and construct a toll plaza. Traffic approaching the plaza is merging from at least two ramps, and traffic leaving the plaza is diverging into at least two directions. There is limited space for vehicle storage in queues before lane access becomes blocked. There is little time for drivers to make decisions on toll lane selection or direction of travel. As a result, ticket system interchange plazas are characterized by slow vehicular movement and weaving through the interchange; relatively low throughput capacity; and a limited capacity of queue storage before impacting merging or diverging traffic. Operations can break down quickly in peak periods. Consider an example of a typical ticket plaza with three entry lanes and five exit lanes, such as the Pennsylvania Turnpike Irwin interchange. The total storage area for the exit lanes after both eastbound and westbound traffic merge might be 100 passenger cars or a smaller number of vehicles if there is a commercial vehicle mix. The five exit lanes can process 180 to 220 vph each or 900 to 1,100 vph collectively. If peak hour traffic to a major intersecting route reached 2,000 vph, the theoretical capacity of a single exit ramp lane, a substantial queue would develop quickly.
Plaza Locations and Growth Limitations
Because of the geometric constraints of the trumpet interchange, it is often difficult or impossible to widen these plazas beyond a relatively small number of lanes. To fit in additional lanes, designers must use substandard taper rates, storage lengths, roadway slopes. The addition of multiple lane types and non-stop electronic toll collection (ETC) lanes in ticket-system interchange plazas is difficult. Limited sight distances, quick driver decision making, and little room for weaving and merging (often only 300 to 500 feet) are characteristics of ticket system interchange plazas.
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