AN EXPERIMENT ON DRIVERS’ ADAPTABILITYTO OTHER-HAND TRAFFIC USING A DRIVING SIMULATOR
Koji Makanae, Prof.,
Miyagi University;
koji@makanae-lab.jp

http://www.myu.ac.jp/~makanae

Maki Ujiie,
ARRK Corporation

ABSTRACT: Traffic orientation is of two types—left-hand traffic (LHT) and right-hand traffic (RHT). With theincreasing cross-border movement of people and the development of worldwide motor vehicle traffic network, thedifference in traffic orientation becomes a barrier in the international traffic environment. The objective of thisstudy is to clarify drivers’ adaptability to other-hand traffic (right-hand traffic for Japanese drivers) by conducting
an experiment with a driving simulator, which can easily switch the traffic orientation. According to the results ofthe experiment, most of the subjects recorded route mistake in the experiment and feel uncomfortable in the otherhand traffic orientation, and half the subjects recorded route mistakes in the experiment.
KEYWORDS: Right- and Left-hand traffic, Driver’s Adoptability, driving simulator, worldwide traffic network

1. INTRODUCTION
Vehicles travel on the left or right side of the road. The Convention on Road Traffic agreed upon in Geneva in 1949
stipulates that each contracting state should adopt an uniform travel system but has not defined any standard
international vehicular travel system. At present, 75 countries and regions adopt the left-hand traffic system (LHT)
and 164 the right-hand traffic system (RHT). Several countries have changed the system, mostly from LHT to RHT.
As a result, RHT is now prevalent.
Drivers learn to drive under a particular traffic system adopted in their country. As more people move across thenational border in recent years, opportunities have been increasing of driving under a different traffic system. The
construction of big civil engineering structures such as strait-crossing bridges and tunnels has created global roadnetworks. Then, safely connecting networks incorporating different traffic systems is a present issue. The means forremoving the barriers created by the difference of traffic system include globally standardizing the traffic systemand enforcing drives operating a vehicle across the border to learn driving for adaptation to a different traffic system.
In either way, drivers need to adapt themselves to varying traffic systems temporarily or permanently. Against theabove background, the authors developed a driving simulator (DS) applicable to varying traffic systems. In thisstudy, driver's adaptability to different traffic systems is evaluated by having domestic drivers who have accustomed
themselves to LHT drive under RHT using the DS.

2. SIGNIFICANCE OF TESTS USING A DRIVING SIMULATOR
Studies of driver behavior frequently require testing under special environments or conditions. Tests using actualvehicles under actual conditions involve risks for drivers or surrounding environments in numerous cases. Applyinga driving simulator (DS) to these tests enables the reproduction of a certain point in time under the sameenvironment for numerous subjects because it ensures the safety of subjects and because it can reproduce the test
environment and control test conditions. These benefits are the reasons why DS have been used for various tests andtraining such as the tests of driving burden and the assessment of road design. In order to evaluate how scared thedriver is, Matsui et al. (2002) verified the relationship between the distance between vehicles and driver's scare in
tests using a DS. Tests for evaluating the fatigue of drivers who travel long hours were conducted by Nishida etal.(2003) and others. Thus, DS have been employed as a useful tool for conducting tests that would be difficult
under an actual environment because of the need to ensure the safety of subjects.

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November 5-6, 2009

DS involve high-speed dynamic image processing with the aid of computer graphics that work in cooperation withthe operation of the steering wheel. DS therefore used to be developed based on costly graphics-oriented workstations. In recent years, however, DS systems can be built based on personal computers owing to the advancementof image processing capability of personal computers (ex. FORUM8 UC-Win/Road). In the meantime, DS systems
have been developed for practical application that are equipped with a motion controller capable of representing not
only changes in image and sound but also changes in sense of equilibrium due to acceleration or centrifugal force(Onuki et.al., 2006).

3. DEVELOPMENT OF A TRAFFIC SYSTEM DRIVING SIMULATOR
3.1 Composition of the Driving Simulator
The driving simulator (DS) discussed in this study is intended for a comparative study of driver adaptability at thetime of switchover to a different traffic system. The requirements specified in DS development are the capabilities
of switchover to a different traffic system, specification of road structures on an ordinary road or expressway
according to the switchover, and control of the timing of emergence of other vehicles. Providing high-resolution
pictures is, however, not so important. In this study, therefore, a personal computer-based dedicated DS is developed
and tests are conducted.
FIG.1 shows the composition of the DS developed in this study. The DS is composed of a personal computer (withMicrosoft WindowsXP), driving control system (Microsoft Sidewinder Feedback Wheel) and liquid crystal display
projector. The driving control system is connected to the personal computer via a USB port.
steeringwheel- typedevicepedal- typedevice-+DirectInput( DirectX)
3D View(Perspective)
Road
Data

Visualizer

3FIG. 1: The composition of the DS

Languages used for developing the DS are C# as a basis, OpenGL for drawing and DirectX9.0 for acquiring
operation data from the driving system. Course data can be expressed by XML and DOM (Document Object Model)
is used for data input and output.

3.2 Acquisition of driving data and drawing of the vehicle
The data on the operation of the driving system is acquired using DirectInput. Data on the angle of rotation of thesteering wheel and the degree of acceleration or braking is obtained as integers between 0 and 1000. The data isconverted to the angle of rotation of the steering wheel and acceleration or deceleration to calculate the position ofthe vehicle and generate an image. A DS user interface is shown in FIG.2. As the initial settings for the DS,
whether or not the position of the steering wheel is changed, whether or not dynamic images of other vehicles exist
and whether or not the degree of control is displayed are specified, and drawing is carried out accordingly.

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FIG. 2: The DS user interface

3.3 Acquisition of driving data and drawing of the vehicle
Objects of drawing are the road, accessories to the road, surrounding facilities and oncoming vehicles.
(1) Road
The road object is constructed based on the data on the road alignment composed of straight lines, circular curves
and clothoids; and the road cross section. Based on the object, such objects as crossings, T intersections andinterchanges are also prepared as parts and drawn according to their positions.
(2) Accessories to roadAs accessories to the road, traffic signals, road signs and vegetation are specified. Traffic signals are designed to becontrollable according to time. The drawing function is specified so that the positions of traffic signal supports may
be changed whenever the traffic system is switched. Multiple types of road signs are generated including regulatory,
warning and guide signs. The supports are also re-positioned when the traffic system is switched as traffic lightsupports. Trees can be arranged as vegetation, which is represented by billboards using two textures.
(3) Surrounding facilities
Multiple types of structures can be arranged along the road. Texture mapping is possible for some structures.
(4) Oncoming vehicles
Oncoming vehicles are represented by texture mapping. They are designed to emerge in relation to the position of
the test vehicle.

3.4 Output of travel data
Vehicular travel data is recorded using XML. The current position (coordinates), angle of rotation of the steering
wheel and the degree of acceleration or braking are recorded and output every 0.5 second.

3.5 Construction of an analysis system
An analysis system is built to analyze the travel data recorded by the DS. Graphs and plan views can be drawn forthe speed, time and tracks based on the travel data of a single or multiple subjects.

3.6 Construction of an analysis system
A course editor is generated to facilitate the arrangement of road objects, accessories and surrounding facilities on
the experimental course (FIG. 3). Data is described using XML.

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FIG. 3: The course editor

4. ADAPTABILITY EVALUATION TESTS
4.1 Test method
Tests were conducted for 13 subjects with a driver's license for an ordinary motor vehicle who had never driven
overseas. Ten males and three females of an average age of 22.1 participated in the tests. Test courses were preparedfor LHT and RHT. The course was composed mainly of an ordinary road, expressway and interchanges. The roundtrip course had right- and left-turning curves, merging zones and entries into parking space, which are the key points
when comparing the travel under different traffic systems. Subjects practiced driving for several minutes to getthemselves accustomed to the driving system and travelled under the LHT and then RHT systems. Data such as thetravel speed and tracks was recorded. Questionnaires were distributed to subjects to report the points where they felt
scared. FIG.4 shows the model course map and the points where travel records were compared under LHT and RHT
systems.

FIG. 4: The model course map

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4.2 Test results and discussions
FIG. 5 gives graphs showing the time that the subjects required to complete the round-trip. The subjects required anaverage of 602 seconds, or approximately ten minutes, to go around the course under LHT and an average of 639
seconds, or approximately 10 minutes and 30 seconds, under RHT, 30 seconds more than under LHT. Actually,
however, less time was required under RHT than under LHT because the course is longer under RHT by as long as
900 m owing to the location of the entrances to interchanges and travelling the distance at a speed of 50 km/hr, thespeed limit specified for ordinary roads, took nearly one minute. FIG. 6 shows changes in speed for subject A.
Subjects travelled at a speed of 71 km/hr under LHT and 75 km/hr under RHT. In response to the questionnairedistributed after the test, subjects reported that they got accustomed to simulation under RHT because they firsttravelled on the left side of the road. The time they spent for practice before the test may have influenced the result.

Upper (red): LHT, Lower (Blue): RHT

FIG. 5: The time to complete the round-trip

Upper (red): LHT, Lower (Blue): RHT

FIG. 6: Changes in speed for subject A
Table 1 gives the number of cases where the subjects explicitly deviated from the lane as indicated by the tracks.
Table 2 shows the points where the subjects felt scared based on the results of the questionnaire survey. The numberof cases of lane deviation under RHT was three to four at intersections (1) and (4). Subjects passed intersection (i),the first intersection to pass under RHT, while they were not yet accustomed to travelling on the right side of theroad. They therefore may have taken the wrong travel lane (FIG. 7). The cases of lane deviation increased at thepassage of intersection (4) because it was designed that oncoming vehicles would emerge at the intersection.
Subjects probably took the wrong lane while being distracted by the oncoming vehicles. Actually, a vehicle running

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on the right lane crashed into another. The subject focused attention on one side and may have been careless about
the right-hand traffic. Intersections scored high in the questionnaire survey as a point where the subjects felt
particularly scared.
Table 1: The number of cases where the subjects deviated from the lane
LHT

RHTNo.
1PointParking accessCorrect
11

Mistake2

Correct
13

Mistake
02

Intersection(1)1334Intersection(2)Intersection(3)131309400121301－

107

Entrance of IC(2)1312－10356Intersection(4)Entrance of IC(1)712891Rampway
Exit of IC

11132012121
16Table 2: The scared points from the questionnaire survey
Point
StreetExpressway

Average

Mode

Parking access

3.6

5

Straight way

4.8

5

Inside turn(Right)

2.9

4

Outside turn(Left)

1.8

2

From ramp way to expressway

2.9

4Straight way

4.2

4

From expressway to rampway

3.52※ 1<< scared -- not scared>> 5(a) LHT(b) RHT

FIG.7 : The trajectories at the intersection(1)(a) LHT(b) RHT

FIG. 8: The trajectories at the entrance of ramp way

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Six subjects out of 14 entered the expressway without noticing the different way of installing the entrance at theinterchange (FIG.8). Under a different traffic system, the merging movements of vehicles on an expressway arereversed. Subjects may have taken the same path as under LHT. Numerous subjects pointed out in response to thepost-testing questionnaire that particular attention should be paid.
The conclusion is that improper driving frequently occurs at intersections (during left-turning movements inparticular) and at entrances at the interchange when LHT is switched to RHT. These points are therefore consideredrisk points. Improper driving is ascribable to distractions by other phenomena in such cases where a traffic system
was switched to another or other vehicles emerged after the passage of an intersection.

5. CLOSING REMARKIn this study, the adaptability to RHT of local drivers accustomed to LHT was evaluated, using a dedicated driving
simulator in order to evaluate the adaptability of drivers to varying traffic systems. Numerous subjects actuallydrove improperly under unfamiliar RHT traffic system, running off the road or committing other errors. The posttesting questionnaire survey revealed that many subjects felt scared under RHT. It was also shown that numerous
driver errors occurred when turning at the intersection or entering the interchange and that the emergence of othervehicles including those coming toward the subject caused errors.
In this study, analysis was made based on the behavior of a test vehicle reproduced using a driving simulator and theresults of a questionnaire survey. In the future, driver anxiety or sense of fear needs to be evaluated based on moreobjective parameters through physiological measurement in such terms as the pulse rate and blood pressure.
Increasing the duration of testing is also necessary to determine the driving experience required for adapting to adifferent traffic system. In this study, driving under LHT was simply compared with driving under RHT and apersonal-computer-based simple driving simulation system was developed and applied. In order to increase test
accuracy, it is necessary to conduct tests to evaluate driver adaptability using a driving simulator with motion
control capability that generates a greater sense of reality.
In addition to evaluating driver behavior in testing, studies on social systems are also important. As described inSection 1, the development of global road networks and the growth of international exchanges are likely to make thedifference in traffic system a barrier in transportation. The two traffic systems established separately in different
countries in the 19th century through the beginning of the 20th century remain, dividing the world. Whether theswitchover of traffic systems and different road networks is possible or not under the present mature transportation
environment is a big research issue in the future. Large-scale social experiments may be required. We shouldenergetically make efforts to tackle these issues in the future.

6. References
Forum8 (2009). “UC-Win/Road”, http://www.forum8.com .
Matsui,Y., Kim, J, Hayakawa,S., Suzuki,T., Okuma,S., Tsuchida,N.(2002). “Evaluation of Fearfulness of Driver
Using Three-Dimensional Driving Simulator”, Proceedings of the Human Interface Sympsium 2002,
Sapporo, Japan, Sep. 1-3, 2002, 131-132. (in Japanese)
Nishida, Y., Shirai, Y., Otsubo, T.(2003). “Development of a driving simulator program for evaluation of long-time
drive tiredness.”, Proc. of Traffic Engineering Meeting(JSTE), Vol.23, 97-100. (in Japanese)
M. Onuki, Y. Suda, Y. Takahashi, H. Komine and K. Matsushita, Study on Improving Angular Acceleration Feel ofthe Driving Simulator and its Effects on Drivers’ Behaviors, International Journal of ITS Research, Vol. 4,
No. 1, (2006), 47-52.

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