Reliability of the Driver Behaviour Questionnaire in a sample of novice drivers

The Driver Behaviour Questionnaire (DBQ) is a well-researched measurement instrument that is used widely to assess aspects of driver behaviour that reflect human error, lapses, and deliberate risky actions. The DBQ has been used in a range of cultural settings and is sometimes used as one of a number of outcome measures in road safety interventions. Its use as an outcome measure assumes that it is a reliable measurement instrument, but apart from evidence that the DBQ item scales are internally consistent there is little evidence about its reliability. This study investigated the factor structure, internal consistency, and test-retest reliability of the DBQ using a sample of 822 recently-licensed drivers who completed the DBQ and other questionnaire items on two occasions separated by about 6 months. The results suggest high levels of internal consistency for each of the four item scales and test re-test reliabilities between r=.65 and r=.75. The results support the use of the DBQ as a questionnaire outcome measure in evaluation studies.