Evaluating the Impacts of Optimization Horizon on the Shared Autonomous Vehicle Reservation Request System

Table 2

Notations.

Sets
	Set of vehicles and requests.
	Set of links.
	Set of the requests optimized in the current optimization, .
	Set of the newly arrived long-term reserved requests for the current optimization.
	Set of the newly arrived short-term reserved requests for the current optimization.
	Set of the unfinished reservation requests from the last optimization.
	Set of the unimplemented reservation requests from the last optimization.
	Set of pickup nodes i^p.
	Set of drop-off nodes i^d.
H	Set of all kinds of nodes.
	Set of pickup and drop-off nodes, .
O	Set of initial station nodes.
D	Set of final station nodes.
O^p	Set of nodes o^p.
O^d	Set of nodes o^d.
A	Set of links except the virtual link (o, vd) and (o, d).
A1	Set of service links (i^p, i^d).
A2	Set of relocation links (i^d, j^p).
Parameters
	Optimization horizons in an operation day.
i^p, i^d	Pickup or drop-off node of request i, .
o	Initial station node, .
d	Final station node, .
o^p	Initial node comes from i^p node of last optimization.
o^d	Initial node comes from id node of last optimization.
	Sink node, .
ti^p, ti^d	Time that a vehicle arrives at node i^p or i^d, , .
to^p, to^d	Time that a vehicle arrives at node o^p or o^d.
t (k, l)	The minimum travel time from node k to l.
dis (k, l)	The travel distance between node k and l.
tp (k, l)	The parking time on the link (k, l).
	The time of the rolling horizon.
	The time of the considered horizon.
Ckl	Cost of using link (k, l), .
Cli	Cost of losing request i.
Cfld	Fuel cost from node k to l, .
Cpkl	Parking cost from node k to l, .
Cv	Cost of vehicle depreciation.
F	Fleet size.
lkl	Link capacity of (k, l), .
θ	Buffer time for vehicle relocation.
μd	Distance limit for vehicle relocation.
μt	Travel time limit for vehicle relocation.
fsl	Proportion of short-term reservation requests to total requests.
Decision variables
xkl	The number of vehicles using link (k, l), .