Algorithm 3: Build a Route Summary

Input: $RG$: a tuple ($key$, L), where $key$ is the pair (route, time period) $key$ and L is a list of taxi information  Output: $RSP$: a tuple (a pair (ar, tp), area, first time period, second time period, a route summary)   1 Initialize $RS$ as a route summary;  // compute elements of a route summary   2 $R{S}_{key}$ ← $R{G}_{key}$;   3 $R{S}_{key}.{\mu }_d$ is calculated from each group $R{G}_{key,L}$; // Equation (5)   4 $R{S}_{key}.{\mu }_{tt}$ is computed from $R{G}_{key,L}$; // Equation (6)   5 $R{S}_{key}.{\mu }_c$ is calculated from $R{G}_{key,L}$; // Equation (7)   6 a destination area $a{r}_d$ ←$R{G}_{key}.\mathtt{getDestArea}\left(\right)$;   7 an origin area $a{r}_o$ ←$R{G}_{key}.\mathtt{getOriginArea}\left(\right)$;  // compute two time intervals: $t{p}_{min}$ and $t{p}_{max}$   8 ArrivalTimeMapping ($t{p}_{min}$, $t{p}_{max}$, $R{S}_{key}$);  // make an RSP with time invtervals for the extension   9 a spatio-temporal hashkey $hkey$ ← a pair of ($a{r}_o$, $R{G}_{key}.tp$); 10 $RSP$ ← a tuple of ($hkey$, $a{r}_d$, $t{p}_{min}$, $t{p}_{max}$, $RS$); 11 return $RSP$;