content name:
  Sleep related crashes have received increasing attention over the past decade. Driver support systems that are able to detect sleepiness and warn the driver could be a potential countermeasure to reduce sleepiness related crashes. The aim of this study was to evaluate a warning system in an experimental investigation performed in a real time car driving application. An additional aim was also to examine the suitability of using an experimental vehicle at test track for evaluation of a sleepiness warning system. The modalities used for warning was a combination of sound, vibrations in belt and spoken messages. In addition a hand worn confirmation button was used. In total 40 participants drove at a closed test track during night (00h–05h). They were instructed to sleep between 01.00 and 07.00 for two nights prior to the night of the experiment. The design of the study was a between group, with 10 participants in each group. The four different groups experienced one of the following: A: No warning – baseline; B: SENSATION warning system with an early trigger; C: SENSATION warning system with a late trigger; D: Feedback (DMS – Siemens) and warning with a late trigger. The trigger of the warnings was based on observer registrations of the driver and driver behaviour. The drivers were instructed to drive a distance of 110 kilometres. The car was a Volvo 850, equipped with sensors in order to measure driving behaviour (lateral position, speed, steering wheel angle). As sleepiness indicators blink duration was used (mean and sd), measured with EOG. After the drive the participants answered a questionnaire. The experiment focused on comprehension, usability, effectiveness, and acceptance. There was no significant observable difference between the groups that received the warning at an early point, at a late point, or at a late point in combination with a feedback system. Regarding the self reported measures, it should be noticed that no participant considered the warning to be too early. The sound was seen as most disturbing and most effective. The belt vibration was seen as least disturbing, but also as least effective. These results seem to be highly related to the level of the sound and the amplitude of the vibrations. In total, 27 out of 30 drivers in group B-D reported they had experienced warnings. About 50 per cent felt that the warning had come at the correct time, and no driver found it to be too early. More than 70 per cent stated that the warning had influenced their driving and 85 per cent thought it had made them more awake; 55 per cent stated that the warning had helped them to stay awake. The warning was easy to understand, and the drivers felt that it was clear what was expected from them. No clear feedback was given when pressing the confirmation button, and so some users pressed the button several times. Confirmation feedback to the user is necessary. Almost all drivers thought that the warning system would contribute to increased traffic safety, and that it would contribute to the prevention of crashes caused by sleepiness. Even if driving for real on a test track gives higher ecological validity than a driving simulator there is still problems to be solved. Drivers, prepared to be sleepy during night time will most truly accept and agree with a given warning. This will influence the drivers’ acceptance of the system. Additionally, sensors used do not have a high technical reliability for speeds under 50 km /h. However, the present study shows that a test during real driving can be done without any risky situations. The recommendation is to take the next step and move out on real roads with experimental cars equipped with double commands in order to have a high external validity, but still a high control, at least regarding the participants’ preparation and actions under the experiment.
content link: http://www.vti.se/EPiBrowser/Publikationer%20-%20English/N9A-2009.pdf
content language: English
English summary: no
If you want to rate, please register or log in.
user comments  
This content is related to:
project type
National projects 
area of interest
user type
research labs 
Other similar contents:

The similarity algorithm calculates how much two contents in the system are similar to one another. So far, similarity is calculated based on similarity of the project type, area of interest and user type. Generally, if two contents have more parameters in common they are more similar to each another. More information.

content description similarity (%)
Results of a field study on a driver distraction warning system  An extended field study on driver distraction and drowsiness was conducted in an instrumented vehicl ...  100 
Traffic safety measures and observance. Compliance with speed limits, seat belt use and driver sobriety  On behalf of the Swedish Institute for Transport and Communications Analysis (SIKA) the effect on tr ...  87.5 
The traffic safety situation among foreign born in Sweden – Based on eight road user population zones  Road traffic crashes are identified as a world wide public health problem. Prognoses by WHO suggest ...  87.5 
Distraction and drowsiness – a field study. Technical report  The scope of the report is to discuss the efficiency effect of different methods for friction contro ...  79.17 
Automatic analysis of eye tracker data  The movements of a person's eyes are an interesting factor to study in different research areas wher ...  75 
The Effects of Commercial Electronic Variable Message Signs (CEVMS) on Driver Attention and Distraction: An update  Review of research concerning the possible effects of Commercial Electronic Variable Message Signs ...  75 
BASt Report: Effects of new vehicle concepts on the infrastructure of the federal trunk road network  BASt studied the “Possibilities for use and effects of 60 t trucks on federal trunk roads" The ...  70.24 
Influence of Roadway Surface Discontinuities on Safety  TRB’s Transportation Research Circular E-C134: Influence of Roadway Surface Discontinuities on ...  67.5 
TRL235 Traffic calming: vehicle generated ground-borne vibration alongside speed control cushions and road humps  This report describes a study to assess ground-borne vibration levels generated by a wide range of v ...  66.67 
Mineralogy, texture and mechanical properties of anti-skid and asphalt aggregates contributing to urban dust  In northern latitudes mineral dust is formed when cars use studded tires and roads are sanded to obt ...  66.67 
created: Ferenc Rajcsanyi, 02.07.2009 11:54:00
last modified: Ferenc Rajcsanyi, 18.04.2011 14:27:35