%T Policies to reduce traffic externalities in cities %A Stef Proost %A Bruno De Borger %I Katholieke Uiversiteit Leuven %D 2012 %U https://apo.org.au/node/31549 %X This paper considers various policy measures to reduce traffic externalities in cities, including externality-reducing investments, tolls, emission standards, low emission zones, and bypass capacity to guide traffic around the city center. Using a simple model that distinguishes local and through traffic, we study the optimal use of these instruments by an urban government that cares for the welfare of its inhabitants, and we compare the results with those preferred by a federal authority that takes into account the welfare of all road users. Our results include the following. %9 Discussion paper