The search for alternative factors to chronological age when examining fitness-to-drive in older drivers
: Establishing the relevance of an accessible test OMEDA PLUS

  • Lara Carballo

Student thesis: Doctoral ThesisDoctor of Philosophy


Driver Licence renewal in the UK is currently reliant on age-based measurement. However, at a time when the older populations are expanding globally, there is potentially an element of implicit ageism present in the government’s unchanged policy. Whilst age-related changes may certainly be seen to affect driving, with statistics showing that road junctions provide a particularly complex scenario for the older driver, these changes do not occur at a uniform rate. The markers of ageing are plentiful, and do not advance evenly either within a single individual, or within the older section of the population.
Driving has been reported as being important for independence and wellbeing, and replacing the concept of age with that of functional ability with regards to fitness-to-drive measurements may well provide the opportunity for older drivers, an arbitrarily defined group, to make the choice to retain their driving status safely for longer.
Computer-based driving assessment tool, OMEDA PLUS was built to augment the Object Estimation under Divided Attention test (OMEDA) (Read 2001), to provide an accessible tool capable of measuring fitness-to-drive across age groups by accessing the higher order cognitive function of judgement. The test provides an opportunity to test fitness-to-drive across ages by examining the ability to execute an important component of driving safely, time-to-contact (TTC).
The aims of this research were divided between testing the augmented version OMEDA PLUS to ensure that it was fit for purpose, and also to examine perceived relevance and likelihood of use of the test. In addition, the research sought to explore alternative factors to chronological age that might emerge as effective variables when measuring fitness-to-drive in older adults in the hope of encouraging the debate around questioning age-based policy. Now portable, OMEDA PLUS is easily manipulated by the end user and is able to reach a greater volume of people within the comfort of their communities.
The research employed mixed design methodologies across four studies. Performance on the new version OMEDA PLUS was compared to results generated by the original version, OMEDA, and by the Useful Field of View test (Ball and Owsley 1993), particularly subtest 2 (UFOV2), in order to establish its robustness and relevance to measuring fitness-to-drive. Interviews took place in order to establish the usability, relevance and likelihood of use for the tool. Analyses included in the main, Spearman’s correlations, one-way ANOVA, and Thematic and Interpretative Phenomenological analysis.
Results showed that age continues to be an important indicator for fitness-to-drive across tests which are designed to be sensitive to age, but that on occasion age might be acting in conjunction with other factors. No alternative factor was found to emerge, but hopefully further research would enable more isolation of variables to occur. In terms of the tool itself, it was found to work well providing consistent results, and it benefitted from its new portability. Discussions with participants highlighted a perceived relevance for the existence of OMEDA PLUS, with a willingness to engage with it pending certain ethical and verification assurances.
Date of AwardJun 2021
Original languageEnglish
Awarding Institution
  • Coventry University
SupervisorPaul Herriotts (Supervisor), Andrew Parkes (Supervisor), Alex Stedmon (Supervisor) & Stewart Birrell (Supervisor)

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