The paper considers the application to transport project assessment of multi-attribute value theory (MAVT). The aim is to compare the results of three weighting methods which are used in MAVT: ratio with swings, Saaty scale with swings, and trade-off. An experiment is set up for a decision problem relating to a public transport project. A sample of individuals is asked to provide judgments according to the three methods. The weights obtained by ratio with swings and by Saaty scale with swings show a high correlation, while weights obtained by each of these methods show a low correlation with trade-off. The weight attached to the cost attribute is higher in trade-off, which is implemented as pricing out, than in the other methods; two explanations for this result are proposed: the compatibility principle and loss aversion. The paper also provides insight on how the attributes of transport project alternatives should be described by indicators so that individuals can attach a value to them.