A basic assumption of many scientific theories on the topic of decision making is rational behaviour. However, previous authors assume the existence of behavioural biases in freight transport which impede rational decision making. Hardly any research exists on behavioural biases in freight transport. To address this gap, we carry out a systematic literature review on the influencing factors of freight mode choice and provide empirical evidence for the occurrence of behavioural biases in the logistics sector. Fifteen logistics service providers and six shippers are involved in interviews and a focus group to understand their mode choice process and derive information on the existence of behavioural biases. Several biases showed to exist in the practical decision-making process. For example, decision makers tend to avoid complex options (principle of least effort), they stick to already tried and tested options (status quo bias, zero-risk bias) and they tend to make decisions based on immediate and easily accessible information (availability bias). These biases distort the demand for sustainable freight transport. We therefore conclude with several motivational, cognitive and technological debiasing strategies to reduce the negative impact of behavioural biases in freight transport.