Timely collection of infectious medical waste (IMW) is essential for reducing the risk of cross-infection under China’s standardized epidemic prevention and control measures. Given the limited duration of protective clothing, medical staff work is divided into shifts, whose duration constitutes the boundary of temporal security. This concept differs from the time window constraints in traditional vehicle routing problems, as it emphasizes due dates requiring IMW to be collected before the end of each designated period while ensuring that the interval between two adjacent collections does not exceed the maximum safe storage time limit. Based on urban time‑dependent traffic networks, this paper proposes a multi‑period time‑dependent vehicle routing problem with temporal security constraints. The novelty of the problem lies in incorporating temporal security constraints, where through the matching assignment between hospitals and potential patients, the number of admitted patients in each period is set as a decision variable, thereby influencing the generation quantity of IMW. The resulting cross-period coupling mechanism causes the IMW generation and collection demands across different periods to be closely interrelated. The problem is formulated as a convex mixed-integer nonlinear programming model and solved via an outer-approximation method and a hybrid heuristic algorithm. Benchmark experiments demonstrate the algorithm’s strong performance. Sensitivity analysis further shows that integrating multi‑period potential patient assignment decisions within time‑dependent traffic networks can significantly improve the efficiency of IMW collection, thereby validating the necessity of temporal security constraints and their substantial impact on routing decisions.
https://doi.org/10.1016/j.eswa.2026.131626Cite as:
@article{Lei_2026,
title={Multi-period time-dependent vehicle routing problem for infectious medical waste collection considering temporal security constraints},
volume={314},
ISSN={0957-4174},
url={http://dx.doi.org/10.1016/j.eswa.2026.131626},
DOI={10.1016/j.eswa.2026.131626},
journal={Expert Systems with Applications},
publisher={Elsevier BV},
author={Lei, Dong and Jia, Tao},
year={2026},
month=June,
pages={131626}
}