A proposal has been made to build a new tunnel under the Scheldt river near the centre of Antwerp in
order to relieve traffic congestion on the ring road and in an existing tunnel. The new tunnel is expected
to cost more than €1 billion, and tolls have been suggested to help finance construction and to manage
demand. This paper conducts a preliminary cost-benefit analysis of a new tunnel and three alternative
tolling schemes, and compares them with a do-nothing scenario and an option to toll the existing tunnel
without building a new one. The two tunnels are treated as imperfect substitutes, and a multi-year
accounting framework is adopted that accounts for emissions, accidents and noise externalities, road
damage, revenues accruing to the national and regional governments from existing transport user charges,
and the salvage value of the new tunnel. With the base-case parameter values it is found that building the
tunnel is worthwhile with all three tolling regimes and yields a higher benefit than not building the tunnel
and tolling the old one. Nevertheless, the net benefit from building the tunnel differs appreciably between
tolling regimes, and it is sensitive to the value assumed for the marginal cost of public funds.
