title: Control task substitution in semiautomated driving: does it matter what aspects are automated?
abstract: OBJECTIVE
  The study was designed to show how driver attention to the road scene and engagement of a choice of secondary tasks are affected by the level of automation provided to assist or take over the basic task of vehicle control. It was also designed to investigate the difference between support in longitudinal control and support in lateral control.
  
  
  BACKGROUND
  There is comparatively little literature on the implications of automation for drivers' engagement in the driving task and for their willingness to engage in non-driving-related activities.
  
  
  METHODS
  A study was carried out on a high-level driving simulator in which drivers experienced three levels of automation: manual driving, semiautomated driving with either longitudinal or lateral control provided, and highly automated driving with both longitudinal and lateral control provided. Drivers were free to pay attention to the roadway and traffic or to engage in a range of entertainment and grooming tasks.
  
  
  RESULTS
  Engagement in the nondriving tasks increased from manual to semiautomated driving and increased further with highly automated driving. There were substantial differences in attention to the road and traffic between the two types of semiautomated driving.
  
  
  CONCLUSIONS
  The literature on automation and the various task analyses of driving do not currently help to explain the effects that were found. Lateral support and longitudinal support may be the same in terms of levels of automation but appear to be regarded rather differently by drivers.
authors.affiliation: Institute for Transport Studies, University of Leeds, Leeds LS2 9JT, United Kingdom. o.m.j.carsten@its.leeds.ac.uk
authors.forename: Oliver
authors.initials: O
authors.lastname: Carsten
authors.forename: Frank C H
authors.initials: FC
authors.lastname: Lai
authors.forename: Yvonne
authors.initials: Y
authors.lastname: Barnard
authors.forename: A Hamish
authors.initials: AH
authors.lastname: Jamson
authors.forename: Natasha
authors.initials: N
authors.lastname: Merat
mesh_terms: D001288:Attention; D001331:Automation / Q000295:instrumentation / Q000379:methods; D001334:Automobile Driving / Q000523:psychology*; D003198:Computer Simulation; D005133:Eye Movements; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D013647:Task Performance and Analysis