Monotony of road environment and driver fatigue: a simulator study Professor: Liu Student: Ruby

Motive & Propose Motive –The drowsiness frequently occur during highway driving and that they may have serious implications in terms of accident causation. Propose –To evaluate the impact of the monotony of road environment on driver fatigue.

Reference-fatigue and drowsy driving Summala and Mikkola % of fatal sleep-related accidents in Finland occurred within the first hour of driving. Pack et al.,1995Sleep-related accidents during the early morning hours: 2:00–6:00 a.m. and to a lesser extent during the afternoon period: 2:00–4:00 p.m.

Reference-fatigue and drowsy driving Endogenous factors affect the basic preparation state of the individual when performing the driving task. Like time of day, the fatigue generated with the duration of the task and sleep-related problems. Exogenous which from the individual’s interactions with the road environment.

Reference-fatigue and drowsy driving The ecological approach to fatigue research: Nelson1997Highway design, and especially the lack of stimulation, can play a role in fatigue-related accidents. the environment can influence the development of fatigue-related symptoms.

Reference-the impact of monotony Horne and Reyner1995Sleep was involved in 23% of accidents occurring on monotonous motorways. Survey data from Maycock 1995Tiredness is a contributory factor in 20% of accidentson motorways. Fell1994Sleepiness accounts for 30% of fatal crashes on rural roads. McCartt et al % of sleep-related accidents occur on highways or expressways Shaffer1993Sleep-related accidents may be common on long stretches of motorways, and may account for at least 40% of fatal accidents. Desmond and Matthews 1996Driving performance decreases faster on straight road sections than on curves.

Reference-the impact of monotony Thorevskij et al.1984An increase of EEG theta and alpha rhythms under monotonous conditions. Alpha rhythms indicate a decrease of vigilance and theta rhythms reveal signs of a stress response. Davies and Parasuraman 1982Arousal theory suggests that performance is poor when arousal is either weak or very strong Mackworth1969Habituation theory provides another view of how monotonous stimulation can alter vigilance and alertness.

Method Participants male university students. 2. Driving license 2 years. 3. The mean age is 24.

Method Device 1. A fixed driving simulator. 2. The simulated highways was designed by Canadian geometric route design standards. 3. The subjective level of alertness (SA) was measured by the Likert scale.

Method Procedure 1. All subjects arrived ate the lab at 13: :20 have 5 min practice :30 is the first driving period (40 min) :10 have 15 min break. (walked up and down a four story stairway) 5. 14:25 is the second driving period (40 min). 6. The SA was tested ate the beginning and the end of each driving period. (5 point Likert)

Method The task 1. To drive in the center of the right lane on a straight 2 lane rural highway. 2. Making the wind push in different power and the wind were randomly appear at every 10s intervals. (left to right) 3. Road A presented pairs of pine trees. 4. Road B presented the rural views. (the random trees, houses, farms and pedestrians sometimes shows out on the roadside.)

Method Dependent variables 1.Steering wheel movement. (SWM) 2.The standard deviation of steering wheel movement. (SDSWM) Three type: small (1-5), large (6-10) and extreme (more than 10) 3.Speed. All dependent variables were measured across 5 min.

Results-Time-on-task effect The mean amplitude of SWM increases over time for both periods (P < 0.001).

Results-Time-on-task effect Increasing in the frequency of large SWM, (P < 0.001), but mainly on road A,

Results-Time-on-task effect The fatigue-related changes in SWM were also show an increasing in SDSWM (P < 0.002),

Results-Time-on-task effect All subjects have lower level of alertness after both driving periods than before (P < 0.001).

Result-The effect of monotony The SWM amplitude for road A is somewhat larger than for road B, the difference it is not significant (P < 0.391).

Result-The effect of monotony The subjects made large SWM more frequently when driving on road A than on road B (P < 0.049).

Result-The effect of monotony It is not being statistically significant (P < 0.198).

Discussion-Time-on-task The impact of fatigue appears quite early during each driving session, the peak is occurring during block 5. The time-on-task effect because drowsiness is usually appearing after more prolonged driving periods.

Discussion-The effect of monotony Given a small difference in monotonous stimuli had a small but significant effect on driving performance, greater stimulus variability could have had a more significant impact. The roadside visual stimulation could be used in order to decrease fatigue and drowsiness on road.