Choice of area Dionysos Nea Erythrea Ekali Kifisia

Brief presentation

This web page has been set up as a part of an MSc thesis entitled “A Web GIS app for comparing routing web APIs over proprietary and crowd-sourced road network data”. The object is to provide a viewing tool for the comparison of two routes with identical origins and destinations but different sources. The routes can be visually compared on the map while a comparison of their data is displayed on the side. An additional metric, the Hausdorff distance, is provided together with a visual cue of where this occurs between the two routes to help with the comparison. Details on the metric as well as the whole process can be found in the paper. The routes provided pertain to 4 specific municipalities of Athens and a specific set of points in each area. The routes are not created at the time of display but were performed at a specific past point in time.

How to use this

Begin by choosing one of the 4 provided areas. Identify your two points of choice to be part of the route on the map and select them in the appropriate ‘from’ and ‘to’ dropdown boxes. Use the legend to identify the source, Google or OpenStreetMaps, of each route. If you wish you can use the swap button to see a comparison of the reverse route. When the origin equals the destination, no route is displayed.

In addition, each route can be compared to its return for each source. Select the source for which you want to compare their return routes by ticking the appropriate box. When only one box is ticked, comparative data is provided in the table adjacent to the map. If both tick boxes are selected, you can view all four routes. As the legend suggests, return routes are displayed with a dashed line.

Where Hausdorff distances have been calculated between two route vectors, you can click the show me button to zoom to the line displaying the two nodes from which the distance was calculated. Hit the delete button to remove the line from the map.