1. Comments Stef Proost (KULeuven) Excellent paper –One of the first to look at the choice of instruments from an economics perspective –Forthcoming in Transportation Research B Comments on potential additions

2. Other points 1 Use environmental economics on transport market –Marginal Damage curve noise is uncertain route choice is clearly most important (cfr; Frankfurt example) but you can do something about it (go for low density routes) so local regulations rather than EU regulations make sense –Marg Cost uncertain? –At present: two part instrument: regulation + fines not too bad (if fines are enforced and have relation with the marginal damage)

4. Noise level Marginal cost of abatement Marginal damage of noise Marginal Damage high density Route Marginal damage low density route Marginal abatement Cost high Marg abatement Cost Low

5. Noise level Marginal cost of abatement Marginal damage of noise Marginal damage low density route Marginal abatement Cost high Marg abatement Cost Low

6. Other points 2 Number of users is fixed –If it was variable one would put tax>Marginal damage –Other selection of instruments? Regulations may have some advantage in that case