Institute for Transport Studies FACULTY OF ENVIRONMENT

Shift Work and Driver Fatigue Yvonne Taylor, BEng (Hons), MSc North Yorkshire Police

PhD Student, Institute for Transport Studies

University of Leeds

Supervisors: Dr Natasha Merat, Dr Samantha Jamson

Sleepy Truck Driver

Background

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•  More than 3.5 million shift workers in the UK (Richbell and Chan, 2011)

•  Sleepiness peaks are generally around 0300-0500 and 1400-1600 (Increases in fatigue related road traffic collisions between these times) (Horrocks and Pounder, 2006)

•  Shift Work induced fatigue is a significant risk factor increasing likelihood of accident and injury (Dawson, et al., 2011)

•  Fatigue accounts for up to 20% of serious collisions on motorways and monotonous roads in Great Britain (Horne and Reyner, 1995)

•  Police Shift Work is associated with high prevalence of sleep disorders and self reported drowsy driving (Vila and Samuels, 2011)

•  Various countermeasures used by drivers (most only effective for short periods, if at all) (Horne and Reyner, 1999)

Driving Performance Risks

Driver Performance

Risks

Increased Risk

Fatigue-related?

Countermeasures / mitigation attempts

Work Pressures

Lifestyle Factors

Driver Fatigue

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YaTH Study •  4 Police Forces in Yorkshire and the Humber Region

•  Over 500 responses, 492 fully completed

•  77.6% male, 22.4% female

•  Age range 22 to 61 years

(letour.yorkshire.com)

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Lifestyle

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Yes No

Num

ber

Yes/No

Do you feel that you sleep well?

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Mode of Transport

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100

200

300

400

500

600

Walk Lift / Taxi Bus / Train Pedal Cycle Motorcycle Car Other

Num

ber

Mode of transport

How do you usually travel to / from work?

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Shifts

What shift causes the biggest problem with driver fatigue?

Earlies

Lates

Nights

Other

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Results and conclusions

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•  In the 12 months preceding the study, 5.8% stated they had been involved in a collision or road departure on the way to or from work

•  51.9% stated they had been involved in a ‘near miss’ such as a kerb strike, lane departure or almost had a collision

•  95.7% of these incidents happened on the way home from work •  61.8% had been working a nightshift prior to the incident

•  Police Officers and staff in the YaTH region who responded to the survey clearly suffering from fatigue whilst commuting, vast majority of self reported incidents happening whilst travelling home from a nightshift

Current NYP Study

•  North Yorkshire Police •  Rotating shifts may cause more problems? (Gold, et al., 1992)

•  Morningness/eveningness questionnaire (Horne and Ostberg, 1976)

•  Sleep diary

•  Watch

•  iPad vigilance tasks

Shift Pattern

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Day 1

Day 2

Day 3

Day 4

Day 5

Day 6

Day 7

Day 8

Day 9

Day 10

0700-1600

0700-1600

1400-0000

1400-0000

2200-0700

2200-0700

RD RD RD RD

iHealth

Actigraphy

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Work Date   Shift  

Data Capture date  

Sleep Start Time  

Sleep End Time  

Time in bed  

Fell asleep in  

Hours Slept   Awakened   Sleep

Efficiency  

11/02/15   E   12/02/15   10:20 pm   5:45 am  7 hr 25 mins   5 mins   7 hr 0 mins   5 times   95  

12/02/15   E   13/02/15   10:15 pm   7:20 am   9 hr 5 mins   5 mins  8 hr 25 mins   7 times   93  

13/02/15   L   14/02/15   12:30 am   6:50 am  6 hr 20 mins   5 mins   6 hr 0 mins   4 times   96  

14/02/15   L   15/02/15   11:40 pm   8:00 am  8 hr 20 mins   5 mins  

7 hr 10 mins   9 times   86  

15/02/15   N (F)   16/02/15   7:30 am   2:05 pm  6 hr 35 mins   5 mins   6 hr 5 mins   6 times   93  

16/02/15   N (F)   17/02/15   7:25 am   10:50 am  3 hr 25 mins   5 mins  

3 hr 10 mins   3 times   95  

17/02/15   R   18/02/15   10:50 pm   8:20 am  9 hr 30 mins   5 mins  

8 hr 25 mins   11 times   89  

18/02/15   R   19/02/15   11:00 pm   9:15 am  10 hr 15 mins   5 mins  

9 hr 20 mins   9 times   91  

19/02/15   R   20/02/15   10:25 pm   6:50 am  8 hr 25 mins   5 mins   7 hr 5 mins   12 times   85  

20/02/15   R   21/02/15   10:25 pm   5:10 am  6 hr 45 mins   10 mins  

5 hr 55 mins   7 times   89  

Actigraphy

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Date   Shift  Steps Taken (Steps)  

Distance Travelled (miles)  

Calories Burned  

11/02/15   E   4289   2.02   1846  

12/02/15   E   6775   3.19   1983  

13/02/15   L   6263   2.95   2087  

14/02/15   L   8956   4.22   2206  

15/02/15   N   13019   6.14   2505  

16/02/15   N   6275   2.96   2087  

17/02/15   R   13523   6.38   2415  

18/02/15   R   11464   5.41   2273  

19/02/15   R   20700   9.77   2774  

20/02/15   R   3652   1.72   1827  

Joggle Research

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•  Scientifically recognised cognitive tests

•  Easily portable, tablet based

•  Easy to access, store and retrieve, cloud based data

•  Simple to set up and run

Motor Praxis Task (MPT)

Visual Object Learning Task (VOLT)

NBACK

School of something FACULTY OF OTHER

Digital Symbol Substitution Task (DSST)

School of something FACULTY OF OTHER

Psychomotor Vigilance Test (PVT)

Hypotheses

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•  Disturbed sleep (shifts and family life)

•  Differences between those classed as ‘morning’ / ‘evening’ people

•  Change in performance/reaction time depending on shift

•  Possible variations between age groups and gender

Initial Findings

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•  Only 7 officers to date •  Time consuming study

•  Compliance fairly good •  Only 1 officer ‘morning type’, others neither morning/evening

•  Paper based sleep diaries correlate to watch data

•  Some operational disturbances to be expected

PVT (5 subjects)

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0

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100

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200

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300

350

400

450

E1 (S) E1 (E) E2 (S) E2 (E) L1 (S) L1 (E) L2 (S) L2 (E) N1 (S) N1 (E) N2 (S) N2 (E) E3 (S)

ms

Shift

PVT Mean RT

Mean RT (ms)

Mean RT (ms)

Mean RT (ms)

Mean RT (ms)

Mean RT (ms)

References

•  Dawson, D. et al. (2011). Modelling Fatigue and the Use of Fatigue Models in Work Settings. Accid An Prev, 43(2), 549-564.

•  Gold, D. et al. (1992). Rotating Shift Work, Sleep and Accidents Related to Sleepiness in Hospital Nurses. Am J Public Health, 82(7) 1011-4.

•  Horne, J. and Ostberg, O. (1976). A Self-Assessment Questionnaire to Determine Morningness-Eveningness in Human Circadian Rhythms. International Journal of Chronobiology, 1976:4, 97-100.

•  Horne, J. and Reyner, L. (1995). Sleep Related Vehicle Accidents. BMJ 310:565-567.

•  Horne, J. and Reyner, L. (1999). Vehicle Accidents Related to Sleep: A Review. Occup Environ Med, 56, 289-294.

•  Horrocks, N. and Pounder, R. (2006). Working the Night Shift: Preparation, Survival and Recovery. A Guide for Junior Doctors. Royal College of Physicians.

•  Letour.yorkshire.com (accessed July 2014).

•  Richbell, S. and Chan, K.W. (2011). Permanent Night Shifts in the 24/7 Economy. University of York, The York Management School, Working Paper no 61, ISSN no: 1743-4041.

•  Vila, B. and Samuels, C. (2011). Sleep Loss in First Responders and the Military. In: Kryger MH, Roth T, Dement WC, editors. Principals and Practice of Sleep Medicine, 5th edition, Chapter 72.

Thank You

Any questions?

tsyt@leeds.ac.uk

its.leeds.ac.uk

@FatigueResearch

Collision Research

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www.pinterest.com (accessed 16th March 2015)