Roozbeh EBRAHIMI GOLSHANABADI*1
* Corresponding author
1National University of Science and Technology “Politehnica”, Doctoral School of Transport, Bucharest, ROMANIA
E-mail: roozbeh.ebrahimi@stud.trans.upb.ro; ORCID: 0000-0002-9391-7269
Pages: 17-27. DOI: 10.24193/JSSP.2026.1.02
Received: 02 February 2026
Received in revised form: 23 March 2026
Accepted for publication: 29 March 2026
Available online: 30 March 2026
Cite: Ebrahimi Golshanabadi R. (2026), Headway-Based Multimodal Resilience Assessment of Metro Systems under Disruption: A Service-Level Case Study from Bucharest, Romania. Journal of Settlements and Spatial Planning, 17(1), 17-27. DOI: 10.24193/JSSP.2026.1.02
Abstract. Metro disruptions affect passengers primarily through headway inflation, headway dispersion and temporary losses of spatial coverage. This paper proposes a headway-native, service-level resilience framework that directly links operational disruption responses to passenger-visible performance. Three complementary indicators are formalized: Mean Headway Deviation (MHD) for service regularity, Service Availability Ratio (SAR) for spatial–temporal coverage, and a System Redundancy Index (SRI) capturing alternative-mode provisioning and operational reserves. These indicators are integrated into a time-varying composite resilience function, summarized over the disruption horizon using a normalized area-under-the-curve metric. The framework is demonstrated on a conceptual Bucharest metro corridor under three response strategies: (A) metro-only short-turn operation, (B) standard segment bus bridging, and (C) integrated extended/parallel/customized bridging. Scenario C delivers consistently superior performance, reducing mean headway deviation from +4.0 min to +1.5 min (−63%), restoring availability from 0.82 to 0.95 (+16%), and increasing redundancy from 0.46 to 0.63 (+37%). The composite resilience score improves from 0.54 to 0.78. Sensitivity analysis confirms dominance invariance under all admissible policy weightings, supporting robust planning use. These findings highlight how disruption-response strategies influence dynamic urban accessibility by preserving station catchments and maintaining corridor-level connectivity, thereby supporting more resilient settlement-level mobility planning.
K e y w o r d s: metro disruptions, bus bridging, headway reliability, multimodal resilience, service availability, redundancy