This step reveals the spatial relation between the nearby drivers and clusters

This step reveals the spatial relation between the nearby drivers and clusters. The spatial relationships are achieved based on topological relations of RCC5 (David et al., 1992). The RCC developed by Randell et al. (1992) is a topological approach to spatial representation and reasoning where spatial regions are non-empty regular subsets of some topological space. The intended topological interpretation of C (a, b), where a and b are spatial regions, is that a and b are connected if and only if their topological closures share a common point. There are two usual extensions of RCC which are called RCC8 and RCC5. RCC8 is the constraint language formed by the eight jointly exhaustive and pair wise disjoint base relations DC, EC,PO, EQ, TPP, NTPP, TPP?1, and NTPP?1 definable in terms of RCC-theory and by all possible unions of the base relations (Randell et al., 1992) (see Figure 8).
Another set of jointly exhaustive and pairwise disjoint base relations definable in the RCC-theory on a coarser level of granularity than RCC8 is RCC5 (David et al., 1992). For RCC5 the boundary of a region is not taken into account, i.e., one does not distinguish between DC and EC and between TPP and NTPP. These relations are combined to the RCC5 base relations DR and PP, respectively. Figure 8 shows the abstracted RCC5 relation. It is fundamental that the drivers wish to meet the closest passengers before meeting the passengers. Therefor using RCC5 relations could specify the geometric relations between the passengers and drivers. Figure 9 depicts an example that is the second relation of RCC5 called Overlap (passengers, driver).