Calculating Time-dependent Routemetrics
Timedependent metrics are proposed comparative figures which can be used for better explanation of the results calculated by taking into account timedependent data. Hence the figures could increase the acceptance by the user of a timedependent route calculation
Benefits
- Realtime route calculation
- Better acceptance of calculated routes through comparative figures
Prerequisites
Check if the following prerequisites are fulfilled before you start with the use case.
Concepts
Then following time dependent route metrics can be calculated:
- Let
Ro be the optimistic route; i.e. best route without taking into account the current traffic situation - Let
to(Ro) be the optimistic traveltime on optimistic route; i.e. the needed traveltime to drive on the optimistic route Ro not taking into account the current traffic situation - Let
te(Ro) be the exact traveltime on optimistic route; i.e. the needed traveltime to drive on the optimistic route Ro taking into account current traffic situation - Let
Re be the exact route; i.e. the best route taking into account the current traffic situation. In general this results in a detour compared with the optimistic route Ro - Let
te(Re) be the exact traveltime on exact route; i.e. the needed traveltime to drive on the exact route Re taking into account current traffic situation - Let
to(Re) be the optimistic traveltime on exact route; i.e. the needed traveltime to drive on the exact route Re not taking into account current traffic situation - Let
detourBenefit=te(Ro)-te(Re) be the benefit of driving a detour around congested roads in contrast to driving over them. The detour is not necessarily longer than the original route, but the crucial point is that the detour is different from the original route. - Let
delayDueToTrafficSituation=te(Ro)-to(Ro) be the delay caused by the congestion when driving through it in contrast to the route without any congestion. - Let
delayDueToTrafficSituationWithDetour=te(Re)-to(Ro) be the delay caused by the congestion when driving around it in contrast to the route without any congestion.
To calculate all these metrics, the following technical concepts are used:
- Time consideration scenarios are used to swicth between optimistic and exact calculation.
- Encoded path is used to recalculate the traveltime on a precomputed route.
Programming Guide
// Data
var referenceTime = "2017-01-09T07:00:00+01:00";
// Map
var map = new L.Map('map', { center: [49.6385, 5.9847], zoom: 13 });
// Add tile layer to map
new L.tileLayer.xserver(xServerUrl + '/services/rest/XMap/tile/{z}/{x}/{y}' + '?layers=background,transport,labels,PTV_SpeedPatterns,PTV_TrafficIncidents'
+ '&timeConsideration=SNAPSHOT&referenceTime=' + encodeURIComponent(referenceTime) + '&showOnlyRelevantByTime=false'
+ '&contentType=JSON', {
pane: "overlayPane",
maxZoom: 20
}).addTo(map);
var A = {
"$type": "OffRoadWaypoint",
"location": {
"offRoadCoordinate": {
"x": 5.9556,
"y": 49.6468
}
}
};
var B = {
"$type": "OffRoadWaypoint",
"location": {
"offRoadCoordinate": {
"x": 6.0141,
"y": 49.6355
}
}
};
var outputString = '';
var outputencodedPath = '';
var to_ro = 0;
var td_ro = 0;
var td_rd = 0;
var to_rd = 0;
function calculateSpecificRoute(tct, waypoints, routeOptions) {
xroute.calculateRoute({
"storedProfile":"car",
"requestProfile": {
"featureLayerProfile": {
"themes": [{
"id": "PTV_SpeedPatterns",
"enabled": true
},{
"id": "PTV_TrafficIncidents",
"enabled": true
}]
}
},
"waypoints": waypoints,
"routeOptions": routeOptions,
"resultFields": {
"polyline": true,
"encodedPath": true
},
"geometryOptions": {
"responseGeometryTypes": ["GEOJSON"]
}
}, function(route, exception) {
outputencodedPath = route.encodedPath;
var geoJson = route.polyline.geoJSON;
if(tct == "ExactTimeConsiderationAtStart") {
displayGeoJson(geoJson, '#ffa225');
} else {
displayGeoJson(geoJson, '#2882C8');
}
if(to_ro == 0 && td_ro == 0 && td_rd == 0 && to_rd == 0){
to_ro = route.travelTime;
var EncodedPath = {
"$type": "PathWaypoint",
"encodedPath": outputencodedPath
};
var waypoints = [EncodedPath];
var routeOpt = {
"timeConsideration": {
"$type": "ExactTimeConsiderationAtStart",
"referenceTime": referenceTime
}
};
calculateSpecificRoute("ExactTimeConsiderationAtStart",waypoints, routeOpt);
}
else if(to_ro != 0 && td_ro == 0 && td_rd == 0 && to_rd == 0){
td_ro = route.travelTime;
var waypoints = [A, B];
var routeOpt = {
"timeConsideration": {
"$type": "ExactTimeConsiderationAtStart",
"referenceTime": referenceTime
}
};
calculateSpecificRoute("OptimisticTimeConsideration", waypoints, routeOpt);
}
else if(to_ro != 0 && td_ro != 0 && td_rd == 0 && to_rd == 0){
td_rd = route.travelTime;
var EncodedPath = {
"$type": "PathWaypoint",
"encodedPath": outputencodedPath
};
var waypoints = [EncodedPath];
var routeOpt = {
"timeConsideration": {
"$type": "OptimisticTimeConsideration"
}
};
calculateSpecificRoute("OptimisticTimeConsideration", waypoints, routeOpt);
}
else if(to_ro != 0 && td_ro != 0 && td_rd != 0 && to_rd == 0){
to_rd = route.travelTime;
var detourBenefit = Number(Math.abs(td_ro - td_rd)).toFixed(2) ;
var delayDueToTrafficSituation = Number(td_ro-to_ro).toFixed(2);
var delayDueToTrafficSituationWithDetour = Number(td_rd-to_ro).toFixed(2);
outputString += " detourBenefit: " + detourBenefit;
outputString += "s delayDueToTrafficSituation: " + delayDueToTrafficSituation;
outputString += "s delayDueToTrafficSituationWithDetour: " + delayDueToTrafficSituationWithDetour;
print(outputString);
}
});
}
function displayGeoJson(geoJson,color) {
var jsonObject = JSON.parse(geoJson);
var geoJsonLayer = new L.GeoJSON(jsonObject, {
style: {
color: color,
weight: 8
}
}).addTo(map);
};
var waypoints = [A, B];
var routeOpt = {
"timeConsideration": {
"$type": "OptimisticTimeConsideration"
}
};
calculateSpecificRoute("OptimisticTimeConsideration", waypoints, routeOpt);
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