In this paper we propose a combined land-use and transportation model for work trips with constraints on the road network capacity. A Lowry-type land-use model is used to distribute all the given activities into various residential and employment zones. Trip distributions are based on the equilibrium round-trip cost, which is obtained from a network equilibrium model. A bilevel programming approach is used to determine the maximum number of trips that can be accommodated by the road network subject to the network-capacity constraints.