A traffic simulation model of pedestrian and vehicle forevacuation under natural disaster

Hisatomo Hanabusa
General Manager of Technical Department, i-Transport Lab. Co., Ltd.
Shin-Surugadai BLDG 9F, 3-10, Kanda-Ogawamachi, Chiyoda-ku, Tokyo, 101-0052, Japan
TEL:+81-3-5283-8527, FAX:+81-3-5283-8528, E-mail:hanabusa@i-transportlab.jp
Tadashi Komiya
Researcher, i-Transport Lab. Co., Ltd.
Shin-Surugadai BLDG 9F, 3-10, Kanda-Ogawamachi, Chiyoda-ku, Tokyo, 101-0052, Japan
TEL:+81-3-5283-8527, FAX:+81-3-5283-8528, E-mail:komiya@i-transportlab.jp
Ryota Horiguchi
CEO, i-Transport Lab. Co., Ltd.
Shin-Surugadai BLDG 9F, 3-10, Kanda-Ogawamachi, Chiyoda-ku, Tokyo, 101-0052, Japan
TEL:+81-3-5283-8527, FAX:+81-3-5283-8528, E-mail:rhoriguchi@i-transportlab.jp
Masao Kuwahara
Professor, Department of Human-Social Information Sciences, Graduate School ofInformation Sciences,Tohoku University
Aoba6-6-06,Aramaki,Aoba-ku,Sendai,980-8579,Japan
TEL: +81-22-795-7492, FAX: +81-22-795-7494, E-mail: kuwahara@plan.civil.tohoku.ac.jp

ABSTRACTIn this study, we developed a traffic simulation framework of pedestrian and vehicle toevaluate the evacuation plans under natural disasters. In this paper, we introduce the conceptof our framework and explain the traffic model and the road crossing behavior model ofpedestrian and vehicle in the simulation. This framework has a function to be attached thedisaster event model (link closing and lane closing). And the evacuation behavior model canbe installed depending on the purpose of the evaluation of evacuation measure. As the future
work, we have a plan to apply this framework to urban city and describe the results of someevacuation plans.
Keywords: Traffic Simulation, Pedestrian, Vehicle, Evacuation, Natural disaster
1. INTRODUCTION
In Japan, many researches of evacuation plan under natural disaster are studied on thebackground of our experiences such as the Great East Japan Earthquake and the Great1

Hanshin Earthquake. Oshima et al.[1] evaluated the traffic measures to reduce the congestionin Tokyo on the day of the Great East Japan Earthquake. Erick et al.[2] and Innami et al.[3]installed Tsunami event model to their traffic simulation model and simulated the evacuationof vehicles and pedestrians. In the case of traffic simulation study, it is said that the behavior
models of vehicle and pedestrian under disaster have been implemented in a traffic simulation
model in recent years. However, the knowledge about the understanding of the traffic
situation by disaster and the effective evacuation plan for large area (the whole of city) are far
from accumulated. For example, the latescent bottleneck point when the people evacuate fromnatural disaster by vehicle or by walk should be understand. In this case, the traffic demands
for evacuation from natural disaster should be included not only the vehicles on the road
network but also the people in buildings, homes, traffic facilities and so on. On the other hand,
the impassable roads by fired and collapsed buildings and the heavy congestion of vehicles
and pedestrians by the concentrated inbound traffic should be considered when we make theevacuate plan to guide the people to the safety places. To understand these issues, the traffic
simulation model which can dynamically reproduce the traffic condition (especially queue
spillback, capacity reduction and grid lock) by natural disaster is needed. And it is importantthat the conflicting of vehicles and pedestrians is one of the needs to express the disruption of
the traffic flow. Therefore, we develop the traffic simulation framework with the conflicting
model of pedestrians and vehicles to evaluate the evacuate plan from natural disaster.
2. THE CONCEPT OF SIMULATION FRAMEWORKOur traffic simulation framework is developed to reproduce various traffic situations on roadtraffic under natural disaster and to evaluate the effects of evacuation measures. Theframework has the following concepts.
Dynamic traffic simulation model for the region-wide road network (10 or 20 square km,up to 10000 links).
Layered road network structure for several kinds of traffic modes.
Interactive modelling between pedestrian and vehicle (link capacity reduction by thecrossing behavior of pedestrian and vehicle).
Including route choice behavior with many-to-many OD of pedestrian and vehicle.
Disaster event model (link closure event, lane closure event, destination change event,etc.)

Figure 1 shows the traffic simulation framework. The framework consists of the traffic
simulation model integrated pedestrian model and traffic flow model, the disaster event modeland the evacuation behavior model. The traffic simulation model includes the crossing
behavior model and the interfaces to accept the event requests from the disaster event modeland the evacuation behavior model.
2Figure 1 : Simulation Framework

3. TRAFFIC FLOW MODEL AND PEDESTRIAN MODEL
In this section, we introduce the traffic flow model and the pedestrian model. For the trafficflow model, we prepared the traffic simulation model SOUND (a Simulation model On Urban
road Networks with Dynamic route choice)[4]. The vehicles in SOUND is discretely moved
based on the Newell’s simplified kinematic wave model[5][6] and can be controlled by traffic
signal and the link parameters (link capacity, jam density, free travel speed, saturation flow
rate, number of lane, etc.). SOUND has two types of route choice model (minimum costchoice model and logit choice model based on Dial’s algorithm). On the other hand, thepedestrian model has a simple moving model by the constant speed controlled by the density(number of person) of link referred to Fundamental Diagram (K-V relationship). The
pedestrian model is also installed the same route choice mode l as SOUND.

Figure 2: Basic Idea of the pedestrian model3

Figure 3 and Figure 4 shows the interactive points between vehicle road network andpedestrian network. The traffic flow model and the pedestrian model share some crossing
points on each road network. And the vehicle on the vehicle’s road network performs thestop-and-go behaviour when the pedestrian on the crossing point.

Figure 3: Interactive points on road network

Figure 4: Network structure and crossing behaviour in an intersection

44. INPUT DATA FOR SIMULATIONThe basic input data for the simulation framework consist of the road network data, zone data
and OD table data (time series for each vehicle/person type). In addition, the disaster event
data such as link closure event (the set of event time, closing link id) and the evacuation
behavior data (new OD table and Destination data for evacuation) are needed for the disastersimulation. The new destination data for evacuation can be used the location data of theevacuation place such as school and park. Figure 5 shows the example of network data andzone data, and Figure 6 shows the example of POI map data.

Figure 5: Road network data and zone data

Figure 6: Example of POI data (evacuation place)55. CONFLICTION BEHAVIOR MODEL
In this study, two basic models to express the confliction behaviours between
vehicles and pedestrians are implemented. Figure 7 shows the concept of theconfliction behaviours model. The crossing model has a function that vehicle isstopped when pedestrian is existed (walking) on the crossing point of vehicle’s
road and pedestrian’s road. On the other hand, the capacity reduction model has afunction that the capacity of vehicle’s road (link) is reduced when the density ofpedestrian’s road (link) is high (one of simulation parameters). This situation by
the capacity reduction model is assumed the flooding of pedestrian by theconcentrated to the public space such as train station.

Figure 7: Confliction Behaviour Model

6. EVACUATION MODEL
The traffic impact by the evacuation behavior can be reproduced by the destination change
behavior model and the departure selection model (determination of start or stop trip) for thevehicle and the person which is planned to departure before the disaster event occur. If thevehicles or the persons running on the road network is caught in the disaster (link closureevent) such as tsunami, they are stopped the trip and counted up as the result of victims by thedisaster. Figure 8 shows the image of the disaster event model and the evacuation behaviors inour simulation framework.

6Figure 8: Example of Disaster Event and Evacuation behaviours

7. EFFECT OF CONFLICTION OF VEHICLES AND PEDESTRIANS
Figure 9 shows the calculation result of the effect to vehicle traffic by pedestrian traffic in anintersection (Jimbocho-intersection) in Tokyo. In this case study, we verified the reduction
pattern of the capacity of vehicle traffic by the traffic of pedestrian. The traffic volumes ofvehicle from each direction and the signal timing data are surveyed at peak time from 9:00 to10:00. The simulation is calculated with shifting the traffic volume of pedestrian through theintersection. The conflicting behavior (crossing of vehicles and pedestrians) model and thecapacity reduction model (vehicle’s road) by the pedestrian’s flooding to the vehicle’s road
are implemented. The traffic volume and the average speed of vehicle are declined drastically7

in case of over 2000 (pedestrian traffic). The models will be validated and improved
comparing to the real data as a future work.

Figure 9: Effect to Vehicle Traffic by Pedestrian in an Intersection

8. FUTURE WORK
For the next step, our simulation framework will be verified using the verification manual for
traffic simulation model with disaster and evacuation model by Japan Association for
Earthquake Engineering[7] (JAEE) before the application to case study. JAEE offers the fiveoutputs (vehicle/pedestrian generation, moving speed, route choice, impact of traffic flow by
escape route and congested situation) for verification and three outputs (network data and od
volume data of validation area, simulation result) for validation to describe.
And we have a plan to evaluate evacuation plans for the 23 words in Tokyo using ourframework. Figure 10 shows the target area. The traffic situation in disaster is calibrated byusing the detector data and the probe data in the day of the Great East Japan Earthquake withsome disaster event model based on the hazard map in Tokyo (link closure events and laneclosure events).

8

Figure 10: Target network for evaluation (Tokyo 23 words)

9. ACKNOWLEDGEMENT
This traffic simulation framework was developed in a Research and Development Project
coordinated by National Institute of Information and Communications Technology (NICT).
The authors thank for the DOMINGO (Data Oriented Mobility Information Group) especiallyfor Yosuke Kawasaki from Tohoku University, Kazuaki Etoh and Takeshi Ohata from Oriental
Consultants Co, Ltd., Norihiro Sudo from Japan Weather Association to promote this researchand development.
10. REFFERENCES[1] Daisuke Oshima, Shinji Tanaka, Takashi Oguchi, Evaluation of traffic control policy indisaster case by using traffic simulation model, 19th ITS World Congress, Vienna, Austria,
2012[2] Erick Mas, Anawat Suppasri, Fumihiko Imamura, Shunichi Koshimura, Agent-based
Simulation of the 2011 Great East Japan Earthquake/Tsunami Evacuation:
An Integrated Model of Tsunami Inundation and Evacuation, 41 Journal of Natural DisasterScience, Volume 34, Number 1, 2012[3]Junji Innami, Yozo Goto, Takashi Suematsu, Muzailin Affan, Yudha Nurdin: Developmentof Tsunami Evacuation Simulation and its using as Disaster Educational Program,International Symposium on Earthquake Engineering, JAEE, Vol.1, 2012.
[4] Tohiso Yoshii, SOUND: A Traffic Simulation Model for Oversaturated Traffic Flow on9Urban Expressways, WCTR, 1995.
[5] G. F. Newell, A simplified theory of kinematic waves in highway traffic, part I: Generaltheory, Transportation Research Part B: Methodological, Volume 27, Issue 4, August 1993 ,Pages 281–287[6] G. F. Newell, A simplified theory of kinematic waves in highway traffic, part I: A
simplified theory of kinematic waves in highway traffic, part II: Queueing at freeway
bottlenecks, Transportation Research Part B: Methodological, Volume 27, Issue 4, August
1993, Pages 289–303[7] http://www.jaee.gr.jp/jp10