The First International Symposium on Transportation Network Reliability, Kyoto, 2001
Extended Abstract

EVALUATION TOOLS FOR THE
EFFECTS OF ETC TOLL PLAZA ON
ROAD NETWORKS
Ryota Horiguchi
i-Transport Lab. Co., Ltd.,
Address: 2-12-404 Ageba-cho, Shinjuku-ku, Tokyo 162-0824, JAPAN
Phone/Fax: +81-3-5261-3077, E-mail: poepoe@nishi.iis.u-tokyo.ac.jp
Masao Kuwahara
Professor, Institute of Industrial Science, University of Tokyo,
Address: 4-6-1-504 Komaba, Meguro-ku, Tokyo
Phone: +81-3-5452-6419, Fax: +81-3-5452-6420, E-mail: kuwahara@nishi.iis.u-tokyo.ac.jp
Toshio Yoshii
Associate Professor, Kochi Institute of Technology
Address: Tosayamada Kochi 782-8502 Japan
Phone: +81-887-57-2406, Fax: +81-887-57-2420, E-mail: yoshii@infra.kochi-tech.ac.jp

ABSTRACTThis research purposes to develop practical tools to evaluate the effects of ETC (Electric TollCollection) system on road networks. In this paper, the analytical methodology to evaluate the capacityof toll plaza with ETC is proposed at first. Subsequently, two exiting simulation models, AVENUE andSOUND, are extended to estimate the total effects of ETC on road networks. After these two models
are verified by comparing the analytical methodology, they are applied to the case studies with realnetwork.

INTRODUCTION
This paper purposes to develop practical tools to evaluate the effects of ETC (Electric Toll Collection)system on road networks. ETC is rapidly installed at the expressway interchange in Japan. As ETC in
Japan is based on road-vehicle communication technology, the improvement on the capacity of toll
plaza apparently depends on the diffusion of on-vehicle equipment. In this paper, the analyticalmethodology to evaluate the capacity of toll plaza with ETC is proposed at first. The methodology
considers not only the proportion of the equipped vehicles to the demand but also the usage of1

The First International Symposium on Transportation Network Reliability, Kyoto, 2001
Extended Abstract

upstream lanes for the toll plaza, such as ETC exclusive use or shared use. It is also considered thesituation described in Figure 1, which the queue of non-equipped vehicles spills over the toll plaza andobstructs the equipped vehicles to enter the exclusive lanes. In such case, the capacity of toll plaza will
get worse than the former plaza before ETC installed.

Figure 1. Image of ETC toll plaza where the queue of non-equipped
vehicles obstructs the way of equipped vehicles.

EXTENSION OF EXISTING SIMULATION MODELS FOR ETC
EVALUATION
For the practical applications, it is obviously insufficient only to consider the improvement on thecapacity of ETC toll plaza, because there must be some up/downstream bottleneck sections adjacent tothe toll plaza. An increase of the capacity of one bottleneck will change the demand profile to thedownstream bottleneck. Sometimes, the queue heading to the downstream bottleneck may set backand drops the throughput of the upstream section. When a network becomes complicated, only thedynamic traffic simulations are available to estimate the total performance of the network for practicaluse. Consequently, in this paper, two exiting simulation models, AVENUE (Horiguchi, et al, 1996) andSOUND (Yoshii, et al, 1995), are extended to estimate the total effects of ETC on road networks.
AVENUE is normally applied to surface street networks that may include toll plaza at an interchange.
It involves microscopic traffic flow features such as vehicles, lanes, signal control devices, etc. On theother hand, SOUND can be applied to the road networks widely spreading over large city. It treats
traffic with meso-scopic flow expression and reasonably reproduces shockwave propagation.

VERIFICATION OF ETC EXTENSION OF THE SIMULATIONMODELS
Simulation approach, however, always faces to criticism that the casual relationship between model
parameter settings and the results is unclear like black box, so that it is required to verify the model
behavior by comparing with the result of theoretical analysis (Horiguchi, et al, 2000). For the subjectof this paper, the extension of ETC toll plaza should be verified by comparing the reproduced capacitywith the values calculated with the analytical method proposed here.
Figure 2 shows one of the simulation results of AVENUE in the verification of the extension for ETC
toll plaza. In this case, the simulation result achieves the toll plaza capacity at 748[veh./hr] against thetheoretical capacity value of 778[veh./hr]. Although there are slight differences coming from therandomness in arrival reproduced by the simulation models, the results support that they reasonably
follows theoretical values.

2The First International Symposium on Transportation Network Reliability, Kyoto, 2001
Extended Abstract

Throughput at Toll Plaza(4 non-ET C gate + 1 ET C gate)

1000

Total 748 [veh./hr]Cum. # of veh.

800

Non-ET C Veh.
ETC Veh.

600
400
200
00:03

0:13

0:23

0:33

0:43

0:53

1:03

T ime

Figure 2. Throughput of the simulation result for the verification of ETC
toll plaza of which theoretical capacity is 778[veh./hr]. (AVENUE)

CASE STUDIES OF ETC EVALUATION
In order to demonstrate the evaluation using two simulation models, two case studies are included at
the end of this paper. First case applies AVENUE to the section from Tokorozawa interchange toNerima exit on Kan-Etsu expressway illustrated in Figure 3. In this section, heavy congestions heading
to Niiza toll barrier are frequently seen on holidays. It is expected that the queue will disappear when
ETC is installed at the toll barrier, but the simulation result shows that half of the congestion willremain with newly heading to Nerima exit, where a signalized intersection stands close.

Kan-Etsu Expwy

Niiza TB

Gaikan Expwy

Oizumu JCTNerima Exit
Figure 3. Study area 1 ~ Kan-Etsu expressway
Another case study uses SOUND to estimate the dispersion effects on congestion by additionallyconstructing low-cost exclusive interchange to serve ETC equipped vehicles. Figure 4 shows the study
area along Tomei expressway, of which section from Atsugi interchange to Yokohama interchange. Inthe middle of this section, there exists a remarkable bottleneck besides Ayase bus stop. The distance
between two interchange is now approximately 16 kilometers, and if the distance will be shortened
into approximately 5 kilometers even for the equipped vehicles, the result of the study shows3

The First International Symposium on Transportation Network Reliability, Kyoto, 2001
Extended Abstract

significant improvement for the congestion.

Yokohama IC

Ayase BN
Tomei Expwy
Atsugi IC
Figure 4. Study area 2 ~ Tomei expressway

REFERENCES
Horiguchi, R., Kuwahara, M., Katakura, M., Akahane, H. and Ozaki, H. (1996). A Network
Simulation Model for Impact Studies of Traffic Management 'AVENUE Ver.2'. In the proceedingsof 3rd Annual World Congress on Intelligent Transport Systems, Orlando, U.S, CD-ROM.
Horiguchi, R., Kuwahara, M. and Yoshii, T. (2000). A Manual of Verification Process for Road
Network Simulation Models - An Examination in Japan. In the proceedings of 7th World Congresson Intelligent Transport Systems, Turin, Italy
Yoshii, T. et.al (1995). An Evaluation of Effects of Dynamic Route Guidance on an Urban
Expressway Network. In the proceedings of 2nd World Congress on Intelligent Transport Systems,Yokohama, Japan.

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