The non-existence of an end-to-end path poses a challenge in adapting the traditional routing algorithms to delay tolerant networks (DTNs). Previous works include centralized routing approaches based on deterministic mobility, ferry-based routing with deterministic or semi-deterministic mobility, flooding-based approaches for networks with general mobility, and probability-based routing for semi-deterministic mobility models. Unfortunately, none of these methods can guarantee both scalability and delivery. In this work,we investigate scalable deterministic routing in DTNs. Instead of routing with global contact knowledge, we propose a simplified DTN model and a routing algorithm which routes on contact information compressed by three combined methods. Analytical studies and simulation results show that the performance of our proposed routing algorithm, DTN Hierarchical Routing (DHR), approximates that of the optimal time-space Dijkstra's algorithm in terms of delay and hop-count....