Shortest & Fastest Routes, Isochrone Maps, Time - Distance Matrix using QGIS

hello guys welcome to another tutorial now in this tutorial I'm going to show you how to use a set of points to calculate the fastest and the shortest route from a given origin to a given destination and in the second part of the tutorial I'm going to show you how to use isochrones now for example if you would like to know what sort of an area can you cover from each of these origin points if you were to let's say a cycle in 10 minutes 20 minutes and 30 minutes and finally I'm going to explain to you how we can interpret this kind of a matrix where it calculates the distance and the travel time between each and every origin and destination point in the form of a matrix quite interesting isn't it so without further ado let's go ahead and get started with the tutorial so the tutorial will consist of three different parts now if I first open up this Oris tools by going to web or tools and all his tools over here by the way in case if you haven't configured Oris tools it you can simply go to plugins manage and install plugins and you can get Oris tools installed first before proceeding with this tutorial now as you can see over here in the first part of the tutorial we actually discussed how we can use this advanced directions option to calculate the shortest and the fastest routes between multiple points now in this tutorial I'm going to focus on these batch jobs and from here I can again calculate the shortest and the fastest spots under these directions option by specifying let's say a points layer and that's what we are going to do as the example and in the second part I'll explain how this isochrones work now for example if you would like to know the coverage of area spatially which you can sort of cover from a given specific point let's say in five minutes depending on the road network of that area or if you would like to know sort of the area which can be covered which has a driving distance of let's say 25 kilometers from some originating point so this kind of analysis can actually be done through these isochrones and and I'll be showing you how to do that and finally we will develop a metric now under metrics what we will talk about is actually how to create sort of a metrics depending on given set of origin and destination points now for example let's say we have four points out of which any of the points or even all of the points can be regarded as origins and we have let's say another set of points which can be regarded as destination points so you might be interested in knowing what is the traveling distance from each origin point to each destination point and how long it might take so that's how we develop the metrics basically so so through the metrics we will be able to obtain information pertaining to the distance and the time from each origin point to each of the destination points all right so let's get started first by exploring how we can use this directions option now I'm going to actually use these points one layer as you can see over here so as you can see from the inputs over here you have two preferences you can either calculate the fastest path or the shortest path now just for the demonstration purposes going to go with the fastest spot and the driving mode I'm going to also select driving by car the provider as you can see it's open route service and here's one of the most important parts over here we have to specify a point layer which can be used as an input layer so as you can see okay I do not have any point layers so what I'm going to do is I'm going to maybe close this up for a second and I'm going to create let's say a layer of points which can sort of give an idea about my travel path so let's say I'm going to start I'm going to zoom in to somewhere over here and now what I'm going to do is I'm going to actually create a set of points I can go to the fall to which I would like to save those points and I can right click over here go to new and I'm going to create a new shapefile let's say I'm going to name this as route points and geometry type is obviously going to be points and the rest I think we can leave them as it is the coordinate system is geographic coordinate system epsg 43:26 and even the fields i think we were just good to go into this with I D under the field list click OK and now what you can do is you can simply drag this empty shapefile into your mapping canvas after that you can toggle the editing mode from there you can activate this add point feature and let's say I'm going to select one point and put the ID number as one so that's my that's one of my starting points and let's say my second point will be somewhere over here ID number two and the third point let's say I would like to come somewhere over here alright this is my third point click OK and after that I can save the point simply by switching off this edit mode and save it and now if I open this route points you can see that my first point is over here second point is over here and the third point is over here well if that's not so visible what I can do is I can simply go to properties and maybe change the color to be something like blue and maybe increase the size as well all right now it's quite visible all right so now in order to calculate the fastest route all I have to do is select my input points layer which is route points and the layer field ID and the layer ID is actually going to be ID again and the rest keep them as default where my travel mode is actually driving by car and the travel preference is the fastest route all right now I can run and if I close this and let's say if I open and maybe change the symbology to something like this and click apply all right now you can see that it shows me the fastest route which I can take starting from this particular point through this point all the way up to this point just out of curiosity in case if you would like to know what the shortest route would be we can still select the route points as the input and now when I run this you can see that it creates a new layer well both the layers actually in the same name but in case if you would like to make these layers permanent it's essential that you actually save it through this option to a name of your choice but since I'm doing this only for the demonstration purposes actually we can just stick with the temporary layer so what I'm going to do over here is I'm going to maybe change the color to be blue because the previous one has sort of an orange shade yeah so you can see that the second one is the shortest route so the fastest route and the shortest route actually differs a bit over here and primarily somewhere over here as well now just as a side note if you're interested in knowing it why the shortest route is not always the fastest route just imagine that if you have to travel through maybe some sort of nth city area to get from point A to point B well if you just calculate the direct distance then going through the city might be the shortest route but of course you have to take into account the fact that going through a city might result in you getting stuck in traffic jams and stuff so the point is that the shortest route is not necessarily going to be the fastest route could be much faster to actually drive through a longer route you might have the potential to drive much faster to get from point A to point B rather than going through a city area so that's how that differs all right so now let's go to this isochrones option to demonstrate isochrones first let me go ahead and get rid of these two so we still actually work with the points the three points that we have now let's say if you are calculating isochrones from point over here we have the option to actually specifically provide the point four which we would like to generate the isochrones now let's say if you are trying to cycle you would like to know the area's which you can cover if you were to start cycling from a specific point in let's say five minutes and ten minutes and let's say 40 minutes how much of an area can you cover what I'm going to do is I'm going to select this point just to keep things clear from this points which we already had let's say I'm going to start somewhere from this Junction yeah somewhere from here all right so you can see that it actually automatically captured the coordinates as well and now when I hit run what it's going to do is it's going to calculate me three things three three particular areas so as you can see over here it generated a new shapefile a new temporary shapefile and lets UNTAC these other two things for a second so you can see that it shows one boundary in terms of an area so basically what this area at OSU is actually the area which can be covered if I were to cycle for five minutes starting from the starting from that particular origin which I provided now if I were to cycle for ten minutes you can see that the boundary which I can cover starting from that particular origin and in 40 minutes these are the boundaries that I can actually reach to if I were to let's say cycle to a particular direction so that's how to interpret this isochrones now let's say that if you don't want to specify just one point let's say that you already have a points layer like this and you want to calculate the isochrones for each point so you don't actually have to do it manually so I'm going to let's say switch off these zones and if you want to use an existing layer you can always go to this isochrones from layer option and from here you can specify the points layer so I'm going to specify these three points which we already had let's say this I'm going to select foot walking so it'll it'll give us how far we can actually walk for let's say maybe not five minutes we'll start with ten minutes and 20 minutes and let's say 30 minutes and we can run now you can see that if I were to actually start at this point this is the boundary which I can get to if I were to walk to a particular direction within ten minutes twenty minutes and thirty minutes and this applies to the other points as well as you can see over here now you might be wondering if I come back to this isochrones from layer what if we were to calculate the coverage of area not by giving the amount of time that we can perform the certain activity of either walking riding my cycle or driving my car but let if I were to specify a range a particular range instead of giving a particular time that's also possible so in that case what I have to do is I have to come here and change the dimension from time the distance and over here I can let's say provided see if I would like to go for a distance of five kilometers so that's going to be about five thousand meters well not about exactly it's five thousand meters so now what I can do is I can simply specify the points layer over here and let me go ahead and get rid of this one for the time being so that it won't becomes confusing once it generates the result all right so now this will generate the the boundary which can actually be reached all right now we can just run this and see what the result is yeah now you can see that if I were to focus on this point by traveling 5,000 meters in a certain direction this is the boundary that you can actually get to now let's see if you're a bit confused in interpreting this just think of an example like this let's say maybe you can see that from this point to this point it's not that far isn't it maybe I can calculate the length quite easily like this from this point up to this point it's only about five five hundred meters so so why do we have to actually travel 5,000 meters in order to reach to a to an edge which is only 500 meters further from our starting point because we don't have the road access always so let's say even if you want to come to this point you might have to travel through a main road and then get a sort of a walking path and probably come back down over here which might cover about 5,000 meters approximately so that's how to actually interpret this isochrones as you can see over here so I guess you guys got the basic idea and the same applies to actually these two points as well all right so now let's Sternoff these layers and then let's go ahead and discover what we can do with this metrics option when I open these metrics you can see that not two of the main inputs are the starting-point layer and the ending point layer so let's say I'm going to actually expand my area of interest over here let's say all of these are possible starting points for my hypothetical example and let's say I'm just trying to actually travel to the southeastern direction let's say maybe to somewhere over here for example let's say that we have two possible ending points one point is over here and one point is over here so what I'm going to do is I'm going to actually create another point layer by going to new shapefile and over here let's say I'm going to specify those to be destinations and the geometry type is again going to be points and ID I'm going to leave it as it is and now I can simply drag this one and start by going to editing mode and by selecting add point feature over here and let's say destinations should be somewhere over here and in the ID just make sure that you actually put some sort of a unique ID now when I was creating the other three points I put the IDs as 1 2 & 3 so we're here just distinguish maybe I'm going to go ahead and put the IDs let's say 10 and my second possible destination let's say somewhere over here and that ID I'm going to put it as 11 so 10 and 11 after that I can switch off the editing mode by clicking on this button and coming back to the points again if I go to the attributes table so these are the starting points you can see that point number 1 2 & 3 and these are the destination points with IDs 11 and 10 all right so I'm going to go go back to this matrix option and as the input start point I'm going to select this route points because any of these points could potentially be my starting point or the origin for my trip and the field is ID and any of these points could potentially be my destinations so I'm going to select that point as that point layer as destinations and yeah the idea is going to be still the ID and since you are covered by the significant area I'm going to use the travel mode as driving by car and then we can simply go ahead and run this all right now you can see in the layers panel a new item call metrics got generated isn't it and I can right click on it and go to the attributes table and look what we have here now the easiest way to interpret this would be to actually double click on this from ID so what it does is actually sorts all the ID numbers starting from the lowest to the highest so now the way to interpret this would be if you were to go from ID number 1 to ID number 11 now if you can recall my ID number 1 is this one ID number 11 is this one let me just go ahead and maybe add the labels so that it'll be quite clear for you guys single labels ID and ok and the same for the destinations as well and if it helps maybe I can reduce the transparency of the base layer so that will increase the transparency of the base layer so that it'll be much more visible all right now let's get back to these metrics by going to the attributes table and what I was just explaining was that if you were to get from ID number one that means this point to ID number 11 which is this point your duration will be about one point three eight hours and your destination and your distance will be 112 kilometers and let's see if you would go from ID number one up to ID number ten point your duration will be a bit less one point two hours and your distance will also be less one 107 point four kilometers now this is a matrix of all possible combinations starting from 1 up to 11 covering all the ID numbers 1 2 3 10 and 11 so you can see that there are two choices for point number eleven point number one you can go either from point number 1 to 10 or 1 to 11 and similarly from 2 to 10 or 2 to 11 and similarly you can go from 3 to 10 or 3 to 11 so that's those are the combinations that we have over here and from here actually we can make a very informed decision especially if it's relates to the type of work that you are doing which involves transportation and knowing these kinds of information easily come in handy to make certain decisions so that's the kind of purpose which this matrix options serve which we can use quite simply using these ORS tools of qjs so I guess that's about it for this tutorial if you do have any questions regarding what we discussed today then don't forget to come in them down below and we'll get back to your queries as soon as possible so thanks a lot for watching the tutorial guys I'll see you again soon with a new tutorial

Channel: GeoDelta Labs

Views: 9,199

Rating: 4.9238095 out of 5

Keywords: QGIS, ORS Tools, Isochrone, Maps, shortest, fastest, network analysis, GIS

Id: Ed5K3SIA1m0

Length: 16min 36sec (996 seconds)

Published: Wed Jul 08 2020