The authors thank Bridget Dicker and Dave Richards from St John Ambulance Services New Zealand for helpful discussions and data. The authors also thank the organizers of the First International Workshop on Planning of Emergency Services, which included a discussion of Jansma (2014) that partly inspired this work. The authors are grateful to Verity Todd and Nick Garrett for providing them with a detailed relationship between demographics and OHCA rates in New Zealand. The authors thank Sam Ridler for providing them travel times for EMS vehicles in Auckland, the Research Software Engineering & Consulting (RSEC) team at RSM for data storage support, and M. Eng. students Jui-an Wang and Lars Kouwenhoven for coding assistance. Some of this work has been executed under the TKI Dinalog grant 2023-1-307TKI.