Road characteristics and driver fatigue

Together they form a unique fingerprint. View full fingerprint. Traffic Injury Prevention , 8 3 , Oron-Gilad, Tal ; Ronen, Adi. In: Traffic Injury Prevention. In: Traffic Injury Prevention , Vol. Understanding of thisdependency of fatigue symptoms on road conditions is of especial relevance todesigners of technological fatigue countermeasures as well as those of futureroadway systems.

How to Cite: Oron-Gilad, T. Road Environment and Driver Fatigue. The authors hypothesized that drivers adopt different fatigue-coping strategies relative to the demands of the drive.

Study results confirm that decremental changes in driving performance varied among road types. Standard deviation in lane the simulator. The mean and standard After the training session they completed the first SOFI ques- deviation were calculated for each roadblock.

Prior to the beginning of Divided attention DA secondary vigilance task. A vigi- the prolonged drive, while connected to the electrodes, the driver lance secondary task appeared 10 times in each road segment. At the beginning of the drive the driver was reminded they noticed a change in the length of the line-segments making once again to respond to the divided attention secondary task.

If no response was registered within five Every 25 minutes the driver was interupted by the experimenter seconds it was regarded as a miss. At Electrophysiological monitoring. ECG signals were the end of the drive, the driver again filled out the SOFI ques- recorded from two skin surface electrodes at a sampling rate of tionnaire. Heart Rate HR was calculated by measuring at the wheel, or 3 said repeatedly more than twice in a row that R-R intervals. Heart Rate Variability HRV is a coefficient or he could not continue to drive, which caused the experimenter to modulation index, the measure is standardized by dividing the end the session.

Drivers were told in advance that the drive would standard deviation of of R-R intervals time domain by the take approximately three hours; they were not aware of the other average R-R interval de Waard, An increase in HRV criteria for ending the experiment.

Note that drivers who expe- indicates an increase in fatigue. Due to large variability among rience simulator sickness symptoms are immediately allowed individuals, physiological measures are always calculated to stop driving.

Usually, individuals who are more suceptible relative to the individual driver i. This measure is similar to the any simulator sickness symptoms. Borg scale, a simple method of rating perceived exertion, although scales of this form are more commonly used for esti- RESULTS mating physical effort.

The average driving time was 92 minutes s. Only two drivers The same experimenter was present in all ten drives. The ex- completed the tenth roadblock.

The results obtained for each perimenter was instructed to look for consistent eyelid closures measure in Table I are given for each measure separately. Performance measures were calculated for each roadblock sep- Procedure arately Table II. Due to the different characteristics of the road Drivers arrived at the lab one at a time around AM after segments making up the complete drive, it is not meaningful to a night sleep of at least 7 hours. At first they completed a de- note incremental changes in performance continuously.

Instead, mographic questionnaire. Then they were given a trial drive on since each specific segment was presented twice or more during Table II Performance measures in Experiment 1. Comparisons have been made between identical road blocks. Those appeared at various stages of the drive; and the number of each road block represents its sequential order within the drive.

Block 7 Block 1 vs. Block 6 Block 2 vs. Block 5 Block 5 Vs. For three drivers head nodding appeared after an average t-test 1 tailed , of 75 minutes s. Lack of energy 1. Sleepiness 1. Specifically, roadblock 3 was com- segments were in one group and the fourth to ninth segment pared to roadblock 7, as those were the two straight roadblocks were in the second group, this may indicate that HRV increased within a drive; roadblock 1 was compared to roadblock 6, as significantly toward the end of the fourth driving segment or those were the two windings roadblocks; roadblock 2 was com- the beginning of the fifth driving segment Approximately af- pared to roadblock 5 and roadblock 5 was compared to roadblock ter 45 minutes of driving.

Figure 1 presents the average HR, 8 as those three roadblocks were of the 4-lane highway. A significant drop The results demonstrate that the driving task itself induced in response rate was found only between the two straight road fatigue. Fatigue symptoms occurred anytime between 45—75 minutes of simulated driving depending on the measure. None Subjective Measures of Fatigue of the drivers managed to complete the entire driving scenario. The SOFI showed significant differences in three dimensions of fatigue; physical exertion, lack of energy, and sleepiness for the before and after measurements, respectively.

The greatest effect was in the sleepiness scale, as shown in Table IV. Rates are given relative to the initial level of the drive.

The remaining eight drivers did. Experi- roadblocks. HRV changed significantly over time, and it is pos- ment two was conducted on university students, a different driver sible that the effect of time on task was dominating, possibly population slightly older in age. For the driving performance measures, we found that 1 there Method was a significant performance decrement between roadblocks of Participants. Sixteen undergraduate students from the de- the same type, and 2 that decrement was manifested differently partment of Industrial Engineering and Management with a for each type of road.

On the winding road the change in per- valid driving license. Participants received course credit for formance appeared in the longitudinal speed, with speed being their participation in the experiment. The average age was 27 significantly higher in Block 6 than in Block 1.

No significant s. Same as in experiment one except that found.