This paper presents a bandwidth-efficient low-delay routing protocol for mobile ad hoc networks called HARP - hybrid ad hoc routing protocol. HARP is a hybrid scheme combining reactive and proactive approaches. The routing is performed on two levels: intra-zone and inter-zone, depending on whether the destination belongs to the same zone as the forwarding node. We propose a new architecture that separates topology creation from route determination. This architecture optimizes routing performance according to two criteria: network properties and application requirements. Topology creation generates a logical structure with respect to network properties, and the routing protocol discovers and maintains paths to satisfy application requirements.