I am interested in measuring speeding driving behaviour through the drivers' speeding intention which according to TPB it includes measuring the drivers' attitude towards speeding, perceived norm, perceived behavioural control and intention.
I believe that a seat-belt use questionnaire based on TPB was developed by prof. Timo Lajunen (SEARCH "Social psychology of seat belt use: A comparison of theory of planned behavior and health belief model" in RG). Perhaps it helps you in designing your speed-behavior questionnaire.