Proceedings of the 9th U.S. National and 10th Canadian Conference on Earthquake Engineering
Compte Rendu de la 9ième Conférence Nationale Américaine et10ième Conférence Canadienne de Génie Parasismique
July 25-29, 2010, Toronto, Ontario, Canada • Paper No 232

FUNDAMENTAL STUDY ON THE DEVELOPMENT OF AＬGORITHM
FOR ROAD DAMAGE ESTIMATION DUE TO NATURAL DISASTERS USINGPROBE-CAR DRIVING DATA
Takeyasu Suzuki1 and Naoki Ohshima2ABSTRACT
In order to bring out the realization of effective disaster response activities bycollecting road damage information as early as possible after a disaster occurs, theauthors propose the adoption of road damage estimation system using probe-cars.
In this system, when a probe-car enters the hazardous area when an earthquake
occurs, for example, sensors equipped with in the car starts to detect anomalous
driving data. Analyzing these data, road damage such as road closure due to slope
failure can be estimated and it is sent to the server computer of road damage
estimation system operated by a road administrator. In order to verify a possibility
to develop such a system, it is necessary to construct the algorithm, which can beapplied to road damage estimation using actual driving data. In this paper, driving
experiments are carried out to measure driving data which represent the two
typical anomalous driving, such as (1) opposing lane driving, (2) turning around,both of which are conducted to avoid failed earth. Then, a simple algorithm isdeveloped using the data. The road damage estimation simulation is developed byapplying the algorithm. Numerical values governing parameters for road damage
estimation are determined by driving experiments with four different drivers andtwo different types of cars. In conclusion, the authors summarizes a prospective
to establish effective disaster response using information sharing of road damage
information among not only a road administrator but various public agencies
relating to disaster management using an information sharing system and generaldrivers using a car navigation system.

Introduction
Road damage information is one of the most important issues for disaster responses in anatural disaster. It is also, however, one of the most unavailable information. Due to both a longroad extension and a multilayered structure of road administrators, not only a collection but
1Professor, Interdisciplinary Graduate School of Medicine and Engineering,, University of Yamanashi, 4-3-11,Takeda, Kofu, Yamanashi 400-8511, Japan
2Director, Falcon Co., Ltd., 4F Miyoshi Building., Soto-kanda, Chiyoda-ku, Tokyo 101-0021, Japanuniform management of road information during a disaster is difficult. Then, the authors
proposed the map of vehicular swept path which is road routes probe-vehicles actually havedrove. The Niigata-ken Chuetsu-oki earthquake of 2006 confirmed its effectiveness [Hada, Y,Kodama, N., Suzuki, T., Suetomi, I. and Meguro, K., 2007]. The proposed map was delivered by
the authors to the disaster countermeasure office of Kashiwazaki City where a severe damage
was occurred due to the earthquake [Suzuki, T., Hada Y., Shimora, H., 2007]. It is a matter ofcourse that the map of vehicular swept path is important, but road damage information is stillrequired for the purpose of early recovery. Therefore, the authors propose the road damage
estimation system using probe-car which enables us early collection and aggregation of roaddamage information and information sharing among stakeholders [Suzuki, T.,et al., 2008].
As a first stage of its development, the algorithm estimating road damage from anomalous
vehicle driving due to slope failure, using the measuring instrument composed of GPS,
gyrocompass, accelerometers equivalent to those equipped with in an in-vehicle unit for ordinary
car navigation systems. In this paper, the development of road damage information system isreported, focusing on driving experiments conducted to develop the algorithm for road damage
estimation.
Concept of Road Damage Information System
Fig.1 illustrates a schematic representation for the road damage information system that theauthors have proposed. The authors suppose that a road administrator manages and operates theroad damage information server. A road administrator, a prefectural government, for example,
provides prefectural employees or consignors with in-vehicle units. In the proposed system,
hazardous areas of earth failure specified by a prefectural government are registered previouslyon the units as the geographical information. When a vehicle enters such zone, an analysis using

Figure 1: Schematic representation of the proposed road damage information system.

the road damage estimation algorithm for anomalous driving is started, depending on the roaddamage situation. Then, the information of detected road damage estimation is sent to the system
server through a communication tool. For example, Yamanashi Prefecture, Japan specifies over
4000 hazardous areas composed of mountain streams inducing mud flow, steep sloping lands,
and landslide areas and they are published on the home page.
By using the road damage estimation, a road administrator easily can set the route for road
patrol and can arrive at a damaged site, which enables not only early affirmation of road damage
but early countermeasures such as closure to vehicle traffic or restoration works. Since the roaddamage information confirmed by a road administrator mentioned above is specified its location
by latitude and longitude, it can be widely shared through public institutions in charge of disastermanagement such as local governments, fire departments, police, or public utility.
Information sharing database shown in the lower right in Fig.1 is the database in which
different organizations can share information using the MISP protocol proposed by the authors[Suzuki, T., 2009]. This study is located in the lower left in the figure.
Execution of Driving Experiment
Cases and Methods of Experiment
Experiments were carried out for two types of diving patterns according to the damage
situation. One is an opposite lane driving on double lane and another is a turning around. Fig.2
illustrates two types of driving pattern. In case of opposite lane driving, in front of failed earth, adriver reduces speed, go at reduced speed, or stops once and go again at reduced speed,respectively. L is the extension of failed earth and is set 5, 10, and 15 meters, respectively. In
case of turning around, on the other hand, a driver stops once in front of failed earth, then backaway for about 10 meters. In order to examine difference among individuals and types ofvehicles, the driving experiment was conducted with four different drivers using two types ofvehicles. The interval for driving experiment is 1000 meter long. Two points were set as adamaged area in the interval. No.1 point is on a straight line and No.2 point is on a curving line,respectively.

(a) opposite lane driving(b) turning aroundFigure 2. Two types of driving patterns conducted in the experiment.

Results of Experiment
The in-vehicle unit used in the experiment equips GPS, gyrocompass and accelerometer, andnot only global position, azimuth direction and acceleration, but velocity, change in velocity ororientation change (degree/second) can be measured. Fig.3 shows a part of experimental results,
in which time histories of driving data in case of opposite lane driving at No.1 point aresummarized in terms of velocity, change in velocity (acceleration) and orientation change. Foursets of these data are classified as each driver, A, B, C and D. In this case, drivers reduce speed
in front of the failed earth and pass the opposite lane at reduced speed.
As shown in the figure, the velocity decreases to the value lower than 10 km/h by reducing(km/h)

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Figure 3. Time histories of driving data in case of opposite lane driving at No.1 point when L =10 meters, summarized in terms of velocity, change in velocity (acceleration) andorientation change
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Figure 4. Comparison of driving data in terms of speed in front of failed earthspeed in front of the failed earth before adriver turns a steeling wheel to an
opposite lane. In the acceleration history,
negative peak of acceleration exceeding 100 cm/s2 can be seen at this stage.
Since a driver turns a steering wheel at
reduced speed, a notable peak with avalue about 10 degrees/s in the time
history of orientation change appears
after the time that the negative
acceleration peak appears.
Passing
through failed earth, a driver turns back asteeling wheel to an ordinary lane. Then,a negative peak in orientation changewith a value about –10 degrees/s appears. Figure 5. Time histories of driving data in case of
opposite lane driving by passing
After that, a driver gains the speed over
10 km/h as shown in the figure. Though
the above-mentioned values are different from each other depending on an individual driver, thetendency is coincident with each other, independently of a type of vehicles and a driver.
Fig.4 illustrates the comparison of opposite lane driving with L = 5 meters among three cases.
In this data, a driver is fixed to driver A. Though the time of negative peak occurrence inacceleration may be a little earlier when L = 5 meters than when L = 10 meters, the tendency
described above is not different even in the three cases. Data measured in the driving experimentwere summarized in the same manner.
Fig.5 illustrates time histories of driving data in case of opposite lane driving by passing. The
data for diver A at No.1 and No.2 points are summarized in the figure. As shown in the figure,the velocity decreases in front of a parked vehicle, but it was not reduced down to 10 km/h.
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Described above, in case of opposite lane driving, anomalous driving can be characterized by thetime histories of velocity, acceleration and orientation change. Thus, the algorithm for road damage
estimation can be developed under the conditions in the followings:(1) A start-up of the road damage estimation system is made, triggering the early earthquake
warning or J-ALERT (Japan quick alerting system on meteorological, volcanic and earthquake
disaster).
(2) The analysis using the road damage estimation algorithm is conducted only when a probe-car
enters the hazardous area.
(3) In opposite lane driving, the velocity decreases to the speed lower than V (km/h) and in thevicinity,(4) A negative acceleration peak with a peak value lower than –amax (cm/s2) appears. Then,(5) Keeping the velocity lower than V (km/h), two peaks with peak values higher than d1 (deg./s)
and lower than – d2 (deg./s) appear successively and after that,(6) The velocity comes back to the speed higher than V (km/h).
In case of turning around driving, a vehicle stops once and backs away the same road, it is easy todetect turning around. In order to determine parameters mentioned above, the examination ondriving data measured in the experiment
was carried out. Then, it was confirmedthat anomalous driving was detected in caseof opposite lane driving, when thefollowing parameters were adopted; V=10(km/h), -amax=-100( cm/s2), t=5s, d1=7(deg./s) and –d2=-7 (deg./s), respectively.
The authors developed a real-timeroad damage estimation system adopting
the algorithm with the above-mentioned
parameters. Fig.6 shows a screen shot of
the developed system. The system works ina mobile computer directly connected with
the in-vehicle unit. Hazardous areas areregistered and plotted by grey polygons inthe figure.

Figure 6. A screen shot of the road damage
estimation system

Concluding Remarks
In this paper, driving experiments were carried out to measure driving data which represent
two typical anomalous driving, such as (1) opposing lane driving, (2) turning around, both ofwhich are conducted to avoid failed earth. Then, a simple algorithm was developed using thedata. The road damage estimation system was developed by applying the algorithm. Numericalvalues governing parameters for road damage estimation were determined by drivingexperiments with four different drivers and two different types of cars. In order to realize roaddamage estimation by probe-cars, algorithms to estimate anomalous driving of a variety ofdamage is necessary.
References
Hada, Y, Kodama, N., Suzuki, T., Suetomi, I. and Meguro, K., 2007, A study on road information sharing
using probe vehicles in disasters, Proceedings of Earthquake Engineering, JSCE, 791-800.
Suzuki, T., Hada Y., Shimora, H., 2007, An approach to delivery of road information in a disaster,Proceeding of the 9th Annual Meeting of Japan Society for Disaster Information Studies, 187-190.
Suzuki, T., Hada Y. and Kodama N., 2008, Study on the provision of ubiquitous disaster information
using probe-car information, CD-ROM, Proceedings of Infrastructure Planning, JSCE, Vol.37,4ps
Suzuki, T., 2009, Peport of the project research on disaster reduction using disaster mitigating
information sharing technology, Proceedings of Japan Earthquake Engineering, Vol.9, No.2,171-184,
Suzuki, T. and Ohshima, N., 2009,Development of the algorithm for road damage estimation due todisasters based on driving experiment data, CD-ROM, Proceedings of Infrastructure Planning,JSCE, Vol.39., 4ps.