The main concern with the IETF proposed Intserv architecture is that the use of per-flow routing and reservation state in the routers may not be scalable to high-speed backbone networks. This paper proposes the Scalable Multipath Aggregated RouTing (SMART) architecture that aggregates flows along multipaths such that the per-flow reservation state in the routers is reduced to a small scalable aggregated state whose size is dependent only on the number of destinations and flow classes. The SMART architecture can be implemented in current IP networks and the complexity is similar to the best-effort IP architecture.