  Hub Labeling (HL) is one of the state-of-the-art preprocessing-based
techniques for route planning in road networks. It is a special incarnation of
distance labeling, and it is well-studied in both theory and practice. The core
concept of HL is to associate a label with each vertex, which consists of a
subset of all vertices and respective shortest path information, such that the
shortest path distance between any two vertices can be derived from considering
the intersection of their labels. HL provides excellent query times but
requires a time-consuming preprocessing phase. Therefore, in case of edge cost
changes, rerunning the whole preprocessing is not viable. Inspired by the
concept of Customizable Route Planning, we hence propose in this paper a
Customizable Hub Labeling variant for which the edge costs in the network do
not need to be known at construction time. These labels can then be used with
any edge costs after conducting a so called customization phase. We study the
theoretical properties of Customizable Hub Labelings, provide an
$\mathcal{O}(\log^2 n)$-approximation algorithm for the average label size, and
propose efficient customization algorithms.
