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Ambulance location and relocation problems with time-dependent travel times.
Verena Schmid1, Karl F Doerner
1Department of Business Administration, University of Vienna, Bruenner Strasse 72, 1210 Vienna, Austria.
European Journal of Operational Research
|December 15, 2010
Summary
Emergency service providers can improve ambulance coverage by accounting for changing travel times. This dynamic approach optimizes vehicle placement, ensuring faster patient response times throughout the day.
Area of Science:
- Operations Research
- Public Health Logistics
- Emergency Medical Services
Background:
- Effective emergency service provision relies on optimal vehicle placement to meet demand.
- Static ambulance location models fail due to dynamic travel times and coverage areas throughout the day.
- Patient coverage is defined by the ability to reach them within a predefined time limit.
Purpose of the Study:
- To develop a multi-period model for ambulance location that accounts for time-varying coverage areas.
- To optimize vehicle repositioning strategies to maintain coverage standards over a planning horizon.
- To address the challenge of effectively locating emergency vehicles to cover potential future demand.
Main Methods:
- Formulation of a mixed integer program to optimize coverage across multiple time periods.
- Application of metaheuristics, specifically variable neighborhood search, to solve the optimization problem.
- Inclusion of time-dependent travel times and coverage variations in the model.
Main Results:
- Ignoring time-dependent variations in travel times and coverage can overestimate the objective by over 24%.
- Explicitly considering these variations improves the solution by an average of over 10%.
- The developed multi-period model demonstrates the necessity of dynamic adjustments for effective ambulance deployment.
Conclusions:
- Dynamic modeling of travel times and coverage areas is crucial for efficient emergency vehicle location.
- Time-varying factors significantly impact ambulance service effectiveness and require dynamic management.
- Optimized vehicle repositioning based on real-time conditions enhances emergency response capabilities.
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