The Value of Preemptive Pick-Up Services in Dynamic Vehicle Routing for Last-Mile Delivery: Space-Time Network-Based Formulation and Solution Algorithms

Table 11

Optimized results for generating initial routing plan in different case scales.

Case number	Number of physical nodes	Number of used vehicles	Running time (s)	Best lower bound estimate	Best upper bound estimate	Relative gap (%)
1	45	9	106	−3517	−3478	1.12
2	70	14	511	−5159	−5021	2.75
3	100	20	1603	−7805	−7479	4.36