Large-network travel time distribution estimation for ambulances

Large-network travel time distribution estimation for ambulances

We propose a regression approach for estimating the distribution of ambulance travel times between any two locations in a road network. Our method uses ambulance location data that can be sparse in both time and network coverage, such as Global Positioning System data. Estimates depend on the path traveled and on explanatory variables such as the time of day and day of week. By modeling at the ...

For Travel Time Estimation for Ambulances Using Bayesian Data Augmentation

There are several constants and hyperparameters to be specified in the Bayesian model. To set the GPS position error covariance matrix Σ, we calculate the minimum distance from each GPS location in the data to the nearest arc. Assuming that the error is radially symmetric, that the vehicle was on the nearest arc when it generated the GPS point, and approximating that arc locally by a straight l...

Travel Time Estimation for Ambulances using Bayesian Data Augmentation

Estimates of ambulance travel times on road networks are critical for effective ambulance base placement and real-time ambulance dispatching. We introduce new methods for estimating the distribution of travel times on each road segment in a city, using Global Positioning System (GPS) data recorded during ambulance trips. Our preferred method uses a Bayesian model of the ambulance trips and GPS ...

Supplementary Material for Travel Time Estimation for Ambulances Using Bayesian Data Augmentation

Travel Time Estimation for Ambulances Using Bayesian Data Augmentation1 by Bradford

We introduce a Bayesian model for estimating the distribution of ambulance travel times on each road segment in a city, using Global Positioning System (GPS) data. Due to sparseness and error in the GPS data, the exact ambulance paths and travel times on each road segment are unknown. We simultaneously estimate the paths, travel times, and parameters of each road segment travel time distributio...