Beyond Heuristics and Commercial Navigation: An AI-Augmented Decision-Support for Ambulance Travel Time Estimation
Authors: Muhammad Adil Abid, Johan Holmgren, Fabian Lorig, Jesper Petersson
Organizations: Department of Computer Science and Media Technology, Malmö University, 21119 Malmö, Sweden · Sustainable Digitalisation Research Centre, Malmö University, Sweden · Department of Health Care Management, Region Skåne, 21428 Malmö, Sweden · Department of Neurology, Lund University, 22242 Malmö, Sweden
Accurate ambulance travel time estimation is critical for emergency medical dispatch, yet existing decision-support practices often rely on static lookup tables or simplified assumptions regarding how ambulance travel time differs from ordinary passenger-car travel. For instance, they assume ambulances simply travel a fixed percentage (e.g., 5%) faster than ordinary passenger cars. However, such assumptions are rarely validated using real ambulance operational data and may fail to capture the effects of trip priority, temporal context, and origin-destination. We address these limitations using historical ambulance trips from the Skåne region in Sweden. Our analysis reveals that ambulance travel times vary substantially by hour, day, and trip priority, and that commercial navigation systems fail to capture emergency-specific dynamics. We contribute a machine learning system to more accurately estimate ambulance travel time. To make the system interpretable, we explored SHapley Additive exPlanations and permutation importance techniques to ensure that our system captures operationally meaningful patterns.
Figures & tables
Figure 1: Mean ambulance travel time by (a) hour of the day, (b) day of the week, and (c) priority level.
Figure 2: A high-level overview of the proposed system’s methodological workflow.
Model
MAPE (%) ↓
MAE (min) ↓
RMSE (min) ↓
R2↑
Polynomial LR
18.73
5.24
10.37
0.65
CatBoost native
13.20
4.84
10.72
0.63
CatBoost one-hot
13.90
4.83
10.50
0.64
Random Forest
19.76
5.79
11.18
0.60
ANN
12.51
4.72
10.15
0.67
Table 1: Comparisons of the machine learning models
MAE (min)
Proposed System (Relative Error Reduction)
Trip Priority
Google Maps
5 % Faster Assumption
Proposed System
vs. Google Maps
vs. 5 % Assumption
P 1 (Emergency)
26.83
24.53
5.58
79.2 %
77.3 %
P 2 (Urgent)
19.50
18.59
4.55
76.7 %
75.5 %
P 3 (Routine)
10.11
9.75
4.78
52.7 %
51.0 %
Table 2: Mean absolute error (MAE) of travel time estimates by priority.
Figure 3: Benchmark comparison of mean ambulance travel time by priority level.
Figure 4: Explainability system analysis: (a) permutation feature importance based on MAE increase after block shuffling and (b) SHAP global feature importance and value distribution.
Emergency medical dispatch increasingly relies on AI-enabled decision support systems when making ambulance dispatch decisions. In this process, accurate ambulance travel time estimates are essential for timely resource allocation and prehospital care. However, existing ambulance travel time estimation approaches typically produce only single point predictions. Consequently, they do not indicate how reliable an individual estimate is or how much uncertainty it carries. This limitation is particularly problematic in safety-critical emergency medical service dispatch operations, where trips with similar expected travel times may exhibit substantially different levels of uncertainty. Furthermore, real-world ambulance trip logs may contain domain-specific artefacts, such as co-located healthcare facilities and physically implausible travel speeds. These artefacts can degrade point prediction accuracy and affect the prediction task on which subsequent uncertainty estimation depends. To address these challenges, we propose an uncertainty-aware methodology for ambulance travel time estimation and evaluate it through a retrospective real-world scenario study using two years of ambulance trip data from the Skåne region in Sweden. The proposed methodology moves beyond average-case point predictions by generating context-adaptive prediction intervals with stable empirical coverage across the evaluated operationally important contexts. The resulting prediction intervals provide explicit information about predictive uncertainty that can support more transparent and risk-sensitive ambulance dispatch decision-making.
Muhammad Adil Abid, Johan Holmgren, Fabian Lorig +1
Department of Computer Science and Media Technology, Malmö University, 21119 Malmö, Sweden · Sustainable Digitalisation Research Centre, Malmö University, Sweden · Department of Health Care Management, Region Skåne, 21428 Malmö, Sweden +1
Ambulance response is time-critical in out-of-hospital cardiac arrest (OHCA), where dispatchers must balance timely arrivals with limited fleet capacity. Static territories and deterministic travel-time estimates are vulnerable to dynamic congestion, while always-dual dispatch adds redundancy but consumes fleet capacity. We propose IDEAL (Intelligent Dual dispatch of Emergency AmbuLances), a selective dual-dispatch framework that sends a second ambulance only when the optimistic gap between primary and secondary paths exceeds a threshold. IDEAL learns context-specific edge travel times from trip-level dispatch records, including unobserved routes, using a weakly supervised bilevel representation network. We train the nonsmooth model with mini-batch conservative gradients and prove an asymptotic convergence guarantee. IDEAL models uncertainty via Burg-divergence perturbations to a shared metric in the learned representation space, thereby inducing correlated changes in edge travel times and learning context-specific radii from historical underprediction errors. For real-time decisions, IDEAL casts optimistic-gap computation as a difference-of-convex program and derives an efficient oracle with complexity guarantees. In collaboration with the Hong Kong Fire Services Department, we evaluate IDEAL using historical OHCA records and real-time adaptive simulations. The results achieve a stronger response-time/resource trade-off relative to all region-based and Google-based baselines.
Zikun Lin, Daniel Zhuoyu Long, Viet Anh Nguyen
Department of Systems Engineering and Engineering Management, The Chinese University of Hong Kong
The ambulance service is the main transport for diseased or injured people which suffers the same acceleration forces as regular vehicles. These accelerations, caused by the movement of the vehicle, impact the performance of tasks executed by sanitary personnel, which can affect patient survival or recovery time. In this paper, we have trained, validated, and tested a system to assess driving in ambulance services. The proposed system is composed of a sensor node which measures the vehicle vibrations using an accelerometer. It also includes a GPS sensor, a battery, a display, and a speaker. When two possible routes reach the same destination point, the system compares the two routes based on previously classified data and calculates an index and a score. Thus, the index balances the possible routes in terms of time to reach the destination and the vibrations suffered in the patient cabin to recommend the route that minimises those vibrations. Three datasets are used to train, validate, and test the system. Based on an Artificial Neural network (ANN), the classification model is trained with tagged data classified as low, medium, and high vibrations, and 97% accuracy is achieved. Then, the obtained model is validated using data from three routes of another region. Finally, the system is tested in two new scenarios with two possible routes to reach the destination. The results indicate that the route with less vibration is preferred when there are low time differences (less than 6%) between the two possible routes. Nonetheless, with the current weighting factors, the shortest route is preferred when time differences between routes are higher than 20%, regardless of the higher vibrations in the shortest route.
Abdulaziz Aldegheishem, Nabil Alrajeh, Lorena Parra +2