FALLING ASLEEP AT THE WHEEL

Certain practical measures to counteract sleepiness under monotonous driving conditions, have been evaluated. Three treatments were given separately during a 30 min rest period between two, one-hour monotonous drives: a placebo (decaffeinated coffee), a nap (less than 15 minutes), and 150 mg caffeine (in decaffeinated coffee). Ten subjects (experienced drivers) underwent all conditions in a balanced design. Sleep was restricted to 5h the night before each treatment condition. An interactive and instrumented driving simulator emulated monotonous driving. Subjects drove between 14:00h and 16:30h. Major and minor lane deviations were identified. Subjects reported their subjective alert/sleepiness levels, and recordings were made of brain (electroencephalogram - EEG) and eye activites (electro-oculograms - EOGs). Video records showed facial/postural changes. Both caffeine and a nap significantly reduced driving impairments, subjective sleepiness, and EEG activities indicative of drowsiness; these effects lasted for the 1 hour duration of driving after treatment. The findings with caffeine were consistent across subjects, whereas those for nap were less so, depending on the ability to nap (most subjects napped). Eye movements (eg eye rolling) were unreliable in determining sleepiness and inferior to the other measures. Changes in driving performance and EEG were closely linked, but there was a small time lag between the two. Subjects were aware of their deteriorating EEG state of alertness almost "on line". Self-knowledge is a good guide to real sleepiness, but subjects may not realise that sleepiness portends sleep, which may descend rapidly thereafter. If one has to drive whilst sleepy, then a break with coffee or a nap can be beneficial, but for only a while. (A)

• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/issn/09684107
• Corporate Authors:

  TRL

  Crowthorne House, Nine Mile Ride
  Wokingham, Berkshire  United Kingdom  RG40 3GA
• Authors:
  • Horne, James A
  • REYNER, L A
• Publication Date: 1995

Language

• English

Media Info

• Features: References;
• Pagination: 26 p.
• Serial:
  • TRL Report
  • Issue Number: 168
  • Publisher: TRL
  • ISSN: 0968-4107

Subject/Index Terms

• TRT Terms: Alertness; Drivers; Driving; Electroencephalography; Fatigue (Physiological condition); Prevention; Safety; Simulation; Steering wheels; Tests; Traffic lanes
• ITRD Terms: 1661: Accident prevention; 2238: Attention; 1772: Driver; 1855: Driving (veh); 2151: Electroencephalography; 2222: Fatigue (human); 9103: Simulation; 1307: Steering wheel; 6255: Test; 2827: Traffic lane
• Subject Areas: Highways; Safety and Human Factors; Security and Emergencies;

Filing Info

• Accession Number: 00715897
• Record Type: Publication
• Source Agency: Transport Research Laboratory
• Files: ITRD, ATRI
• Created Date: Jan 31 1996 12:00AM