Team # 69427 Page 2 of 26
The above studies have their own advantages, the overwhelming majority of them focus on the
impact of existing toll plazas. But these studies do not synthesize these effects to design a solution to
toll plaza traffic difficulties. Therefore, we focus on the design of the toll plaza.
With the support of technology and theory, we developed a mathematical model to determine the
shape, size and merging pattern of the area following the toll barrier. This model can make accident
prevention, throughput and cost most suitable for toll plaza.
1.3 Our Work
When vehicles fan in from
tollbooth egress lanes down to
lanes of traffic , the area
following the toll barrier has a significant impact on accident prevention, throughput and so on.
Specifically, the toll plaza's traffic flow, accident rate, and cost are strongly correlated with its shape,
size, and merging patterns. In order to determine the best design of the toll plaza, we have done the
following three aspects from the performance analysis of any specific toll plaza.
Determine the number of toll lanes: The number of toll lanes are determined by the traffic flow,
the traffic capacity of each toll lane and the level of service. The toll lane capacity is divided into
single-channel capacity and multi-channel capacity. In the case of multi-channel, we choose M /
G / K queuing model to describe the actual operating state of the toll plaza. The queuing model is
also used to describe the traffic flow, which can be used to divide the service level of toll plaza.
At a certain service level, we convert the traffic flow into traffic intensity, which is the matching
conditions of the number of toll lanes.
Design the optimal merging pattern of traffic flow: The merging pattern plays an important
role in the occurrence of traffic flow and traffic accidents. Because of the U-curve relationship
between the ratio of traffic flow to capacity and the accident rate, we establish the optimal traffic
flow merging pattern design model based on maximum throughput and minimum security risk.
Optimal cost calculation of toll plaza: Vehicles across the toll plaza is a process of slowing
down and then accelerating. We assume that the study is carried out in an ideal traffic state in
order to simplify the model. In the process of speed changing, the size of the toll plaza needs to
meet two conditions, namely, the safety distance between the front and rear cars and the actual
braking distance. Based on this condition, we build the optimization model to get the size of the
toll plaza that minimizes the cost.
Test models and analyze performance in different traffic environments: The increase of the
traffic flow makes the service pressure of the toll plaza increase, and we use variable-controlling
approach to analyze its impact on the program. At the same time, we consider the effect of
autonomous (self-driving) vehicles on the model. Autonomous vehicles have only one choice of
toll modes, so it will change the merging pattern of traffic flow. If the proportion of three toll
plaza identified, the design of the toll plaza will be affected by the proportion of the program.
2 Analysis of Overall and Key Points
2.1 Overall Analysis
As an important part of freeway, expressway sub-confluence area and toll plaza design require a
further research. The ultimate goal of toll plaza design is to avoid the traffic accident and the traffic
congestion. After through the toll plaza, vehicles can have the smooth and safe access to the toll lane
to accept the service, and have enough confluence space to drive back to the normal lane. This can
provide a safe, comfortable and efficient working environment for toll collection and toll plaza
management.