Influence that personal attributes of elderly driver gives to driving ability and its secular change- Analysis of physical and mental functions, living conditions, effects of diseases · medication Yasumi Ito1, Tomoya Sakuragawa1, Kei Sato2, Shota Sakaida3, Yoshitomo Orino4, Ryuichi Yamada1,Ryota Okuwaki1, Tsukasa Kouno1, Natsumi Suzuki1, Yoshiyuki Kagiyama1
1．University of Yamanshi, 2．Shigakkan University, 3．TOYODA GOSEI Company Limited,
4．Central Nippon Expressway Company Limited Hachioji Regional Branch
E-mail : yasumii@yamanashi.ac.jp, g17tm007@yamanashi.ac.jp,

I. Investigate the relationship between long-term
driving ability and personal attributes/ mental and physical functions

Abstract
The number of accidents caused by elderly drivers has increased, which has
become a social problem. On the other hand, moving by a car is an importantmeans to support an independent life of the elderly. Therefore, we aim to makelong-term safe driving for elderly drivers possible and prevent accidents.
It has been indicated that health condition, years of education, living
conditions, etc. of elderly drivers affect their driving ability. Therefore, using
databases including items of attributes and characteristics which affect driving
ability makes safe driving of elderly drivers possible for a longer time, and it isuseful for research to prevent accidents beforehand.

•the relationship between driving ability and personal attributes /mental and physical functions
Relationship between driving ability and age

DS score

•

9.0
8.0
7.0
6.0
5.0
4.0
3.0
2.0
1.0
0.0

A

nb=75

na=186570

DS score[%]• According to 2017 estimates, 27.7% 30.0
27.7%
are aged 65 or above. Japan is rapidly 25.0
over 75years old
progressing to an aging society.
13.8
20.0
15.4%
→ the number of driver’s license
65~74years old
15.0
6.4%
holders who are 65 years and above is 10.0
Percentage of
13.9%
5.0
also increasing
population over 65
9.0%
in the world
0.0→fatal accidents caused by elderly
JAPANUSAdrivers is on an upward trend
Comparison of the proportion of elderly Fujikawaguchiko Town Senior Driver Support Project has been continuously
studying how are the physical functions, brain functions, lifestyles, etc. of theelderly related to driving ability, and its secular change from 2008.

Develop skill evaluation method for the elderlyThis experiment was conducted from FY2012 to FY2018 as a part of Fujikawaguchiko Town
※2012 , 2013 carried out in Dec. and Oct.
Senior Driver Seminar.

70s
80s

male：8，female：6
106 people

Implementation month（Times）

male：71，female：35
17 people①Driving Simulator (DS)
②Trail Making Test (TMT) from FY 2014
③Mini-Mental State Examination (MMSE)④Safe driving workbook•Sep.，Nov.※（2 Times）

male：16，female：1

Interview surveys of driving history, education
history, sleeping time, sports experience••

Perform a total of four tasks in each experiment. (The timerequired for each task is about 7 minutes)
The results of the driving experiment are evaluated based on
our proposed standard (1).

Run task screen seen from participants in experiment

16

Years of education• The left figure shows a comparisonof DS scores for age divided by
9.0
8.0
Yonger than 73 y/o73 y/o and older
younger than 73 years old and 73
7.06.0years of age or older.
5.0
4.0• In the group aged 73 years or older,
3.0
2.0
the short-term training effect was
1.0
0.0
seen to be better than the group less1st 2nd
1st 2ndthan 73.
Effect of short-term training on education years • In the left figure, it is a
9.0
comparison of the DS scores by
8.0
Under 12 years
More than 12 years
7.0
classifying education years to less
6.0
5.0
than 12 years and over 12 years.
4.0
3.0• There is an obvious effect from2.0
1.0
driving training who have more
0.0
1st 2nd
1st 2ndthan 12 years’ education.
Effect of short-term training on age② Analysis of the impact on short-term(b)effectsz－ （１Time）

DS score standard(2)How to evaluate driving ability

14Long-term change in driving ability of elderly
driversyDriving attitude survey consisting of dangerous
driving degree and compensation driving degree⑤Questionnaire on driving a car from FY 2014
•12DS score

Driving task

Number ofcollisions

1practice

5+2practice

2-4

3practice
50km/h0-1
5+450km/h

2-4550km/h70km/h

0-1
5+670km/h

2-4770km/h
90km/h0-1
5+890km/h

2-4990km/h

0-1zyx
2th consecutive year(N=13，averagesage: 74.2 years old)

9.0
8.0
7.0
6.0
5.0
4.0
3.0
2.0
1.0
0.0

3th consecutive year(N=6，averagesage:76.5 years old)
4th consecutive year(N=4，averagesage:81 years old)
5th consecutive year(N=2，averages
age: 76.5 years old)

1st

2nd

3rd

4th

5th

Number of times implemented

6th

6th consecutive year(N=1，76yearssold)• By continuing the driving training for multi-years, there is az
positive effectfrom driving training for participants aged 72 years
and over.y• Effects are accumulated even by training twice a year.

2013

2014

2015

2016

2017

decreasing from 2016 to 2017.

DS score for ID24-002 from 2012-2017•

As a result of analyzing the individual attributes of the elderly whose
driving ability has declined,Results of a participant(ID 24-002)
2012
2016
DS score
5
9
TMT A [seconds]
37(2014)39
TMT B [seconds]
80(2014)
78MMSE

29

Accident experience
No(2014)
Fallen experience
Driving time
2hours(2014)
Safety consciousness
Yes(2014)

2017
55892

29

②NoYes

7 hourYes

5 hourYes

29•

From 2016 to 2017, longer
time required for TMT• From the questionnaire
Accident and fallen experience(None → existence)
Decrease in exercise frequency

Document

Information to be acquired

Written Statement

Driver's behavior at the time of driving

Record of actual situation
Written Statement
prescription
Investigation matters inquiry

Accident case1••••

Traveling locus of the vehicle at the timeof the accident
Driver’s situation during accident
Medicinal medicine
Drug concentration in blood etc.
immediately after the accident

From the data in the table,
we got information toregister in health-induced
accident database. As aresult, detailed accident
situation etc. are grasped.

Analysis of traffic accidents

A 26-year-old man, a driver, during treatment for epilepsy
He had a seizure during driving and enters the oncoming lane
Collision on the vehicle that has advanced from the opposite[Written Statement]• In the testimony of the accused, I forgot to drink theantiepileptic drug (carbamazepine) from one month ago.
• In the witness testimony, the accused was in a state ofconvulsions immediately after the accident.
[Investigation matters inquiry]• Immediately after the accident, even if he ingested theantiepileptic drug, the blood concentration does not reachthe therapeutic concentration, so there is a high possibility
that he has forgotten to take the medicine.
•Common therapeutic concentrations・・4～10μg/ml
The treatment concentration of the accused immediately after theaccident・・1.5μg/ml• The health condition of the elderly, years of education, fallen
experience, living conditions affect driving ability.

• One of the most important factors for this accident: the accused have forgotten
to drink the antiepileptic drugs ⇒a health - induced accident

However, in this survey it is unclear whether the fall is ahead or theaccident is ahead, so the root cause is unknown→Further detailed investigation required••••

Analysis of the effect of driving training

DS score

60s

14 people

10DS score

Methods used in this researchContents of implementationExperiment participants8• There was a positive correlation
between DS score and years ofeducation.
• Since the education years
influence a person’s life, it issuggested that the living
condition affects driving ability.

DS score

Micro analysis of the actual accidents’ dataand clarify the causes of those accidents

Implementation content

9.0
8.0
7.0
6.0
5.0
4.0
3.0
2.0
1.0
0.0

6

2012

90 ※ To eliminate the influence of age as much as
possible, participants aged from 73 to 81 years
old who are the same generation were analyzed.

① Analysis of the impact on short-term effects

 Currently, serious accidents(hereinafter referred to as "health-induced accident")
which are caused by physical condition's sudden change such as cerebral
infarction and onset of epilepsy has become a social problem.

•85

Age

nb=75

population in Japan and the United States1）

II.

80

r=-0.36p<0.01

Relationship between driving ability
and education years ※Introduction

Investigate the relationship between long-term
driving ability and personal attributes / mental
and physical functions

nc=1175n=137I.

CB• There was a very high negative
correlation between DS scoreand age.
• It is suggested that driving
ability has declined with age.

The Baltimore Convention Center
1 W. Pratt Street,Baltimore, MD 21201-2499

Investigation materials for extracting data

A Participant whose DS score has declined extremely in the sixth year(ID24-002)
98• Focusing on a participant whose7
6
DS score has extremely decreased
54
from the sixth year.
32• The DS score, TMT - A, TMT - B,
10
the respective results areDS score

UNIVERSITYOFYAMANASHI

February 18-23, 2019

AMERICAN ACADEMY OF
FORENSIC SCIENCES•Accident case2
Rear-end collision accident
Male in forty-age who was rear-ended diagnosed with subarachnoid hemorrhage
A 40-year-old man’s truck running on the right lane collides with the median strip
After stopping in the left lane, a 60-year-old man’s truck collided from the end

If it is possible to investigate health and living conditions from a detailed
analysis of actual traffic accidents, there is a possibility that the correlation
with the accident will be clear.
has stopped

II. Development and verification of healthinduced accident database• A comprehensive survey on health-related accidents has not been
conducted in Japan.
• A detailed database on traffic accidents: such as NASS – CDS(3),ITARDA (Japan), GIDAS(German) etc.
• No data about health and living in Japan.
Outline of health-induced accident database• We made a database referred to NASS - CDS.
Crash Overview

Summary of crew
Injury position
career

General Vehicle

medical History

Clinical History，Taking medicine

Vehicle Exterior

Everyday Life

Meal Situation，Bedtime，Wake-uptime

Vehicle Interior
Safety Systems

Daily exercise
pastimeBehavior during
driving

Occupants
Living conditions，Personal attribute②etc.

Seating position, age, height, weight, sex
Date of death, death, death certificate

Illustration of the state behind thevehicle that was burning a hazard lamp
• Flashes of hazard lamps (report from Central Nippon Expressway Company)→Symptoms of epilepsy and endogenous subarachnoid hemorrhage may have developed
before collision

Conclusions• Elderly people improved their driving ability even in a short period of time bydriving training. In addition, it was found that the effect of training could getaccumulated by receiving driving training for a long period.
• It was revealed that health condition, years of education, fallen experience,living conditions of the elderly affect their driving ability.

②• From the analysis on micro data of traffic accidents :it is useful to prepare a databaseincluding items related to the health condition of elderly drivers, because it is possible
to prevent accidents beforehand based on the database.

[ex.]golf，soccer

Acknowledgments[ex.]Shogi，Reading，Travel[ex.]Music Hearing[ex.]Duty status，Personality• NASS-CDS consists of six items(three hierarchies for more details)
like crash overview, general vehicle, vehicle exterior, vehicle
interior, safety system and occupants.
→Added items of living conditions and personal attributewhich are thought to be useful for health-induced accidents

This work was supported by JSPS KAKENHI Grant Number JP16K12955. I would
like to thank National Research Institute of Police Science, which sponsored a partof this study

References
1)
2)
3)

Ministry of Internal Affairs and Communications statistics Bureau Population of elderly people
https://www.stat.go.jp/data/topics/topi1031.html
Yuta Inaba, Yasuhiro Ito, Yoshiyuki Kurosan, effects and problems of driving rehabilitation system using simple driving simulator, Kanto
branch of the Automotive Engineers' Association, Preliminary Reports of Academic Research Lecture， (2013)
National Automotive Sampling System (NASS) | NHTSA：https://www.nhtsa.gov/.../national-automotive-sampling-system-nass