0
votes
1answer
38 views

how to select line segments not overlapped by other layer's lines

I have two shapefiles of forest roads (mostly dirt) from different sources, covering the same area. The goal is to build one shapefile of roads that is the composite of the other two. Layer A is ...
1
vote
1answer
60 views

How to calculate highway lengths using QGIS?

I need to create a network of highways in 8 states of the USA. Eventually, I need their length, the speed and if possible average daily traffic volume, I don't know how to extract this information. ...
0
votes
0answers
39 views

How to cut a shapefile using a batch?

I would like to cut a shapefile using a batch (like in the photo): But I have some problems because I don't know what do I have to put in field "extent" and after putting somthing like ...
0
votes
0answers
32 views

Why there is no output (path) for Dijkstra in pgrouting

I have a road network table and I am implementing pgRouting. everything was working fine previously but now there is something odd here. I am getting no route now. I am checking through sql query in ...
0
votes
0answers
42 views

I'm looking for an idea to calculate shortest path in a line Vector layer using a starting point

I'm looking for an idea to calculate shortest path time in a line Vector layer using a starting point in a qgis python plugin based on distance and speed. is there a solution where i can get ideas? ...
1
vote
1answer
422 views

Can't select layer in the Road Graph plugin QGIS

I'm trying to use the Road Graph plugin in QGIS 2.2.0. I have tried a few line shape files, but it won't let me select the layer (the option is greyed out). I've tried adding a 'SPEED' field and a ...
1
vote
2answers
78 views

Suggest an algorithm to measure how a node is connected to road network

I try to measure how well a node is connected to the rest of the network. If a city has a distant suburb connected with one sole road, it's connectedness is, say 1. If it's connected by 2 roads, it's ...
1
vote
2answers
41 views

Linking data to road colour scheme

I'm getting started with a qgis map showing the quality of roads in my town. I have various data which create an index of 1-5. How do I link this index data to road data in a map, showing the bad ...
0
votes
0answers
49 views

draw route based on given nodes and existing line

this question is in relation with an application i m building for my project.I have a points layer having all major stations.I have a line layer having the road route connecting the stations.What i ...
7
votes
4answers
251 views

Automatic matching of two street networks

I'm faced with the problem of matching two street networks. I have these two differently sourced networks. The links in each network can be segmented, i.e. there is not necessarily a single whole link ...
2
votes
1answer
344 views

How to get a city road network as line segments?

I want to have road-network information of different cities(New York for example) in the format of line segments(i.e. every road is represented by segment(s)). I want this for experimental purposes in ...
3
votes
2answers
257 views

How to extract all Way elements tagged as highways from OSM data using QGIS?

I want to extract/filter in all Way elements within a specific region tagged as 'highway' from an OSM file. I am currently thinking of using a Python library called osmread (by A Dezhin) that I ...
0
votes
0answers
207 views

Display colour coded road traffic data in QGIS

I would like to colour code a shape file containing road polylines to represent the heaviest flows of traffic. The shape file contains attribute data linked to each section of road where road traffic ...
2
votes
2answers
244 views

Identify points near roadside in QGIS

How do I create an attribute list from points that run along roads in a shape file containing road data? The points don't intersect the road centre lines and are not consistent in their distance from ...
14
votes
2answers
1k views

How can I merge/collapse nearby and parallel road lines (eg. a dual-carriageway) into one single line?

I have a shapefile from OSM which contains all the roads within a city. Larger roads (like dual-carriageways) seem to have 2 parallel lines. I'd like to collapse / combine those into 1 line so I can ...
1
vote
1answer
542 views

Create buffer-lines in QGIS alongside Vector lines

I am currently doing a map of a farm, to see which roads needs to be repaired. Those roads are either one sided fenced, on both sides fenced or not fenced at all. I want to make buffer lines around ...
6
votes
4answers
1k views

How to find dead-ends in a road network

I'm trying to remove all the dead-end roads in a road dataset (lines) that are less than 100m long. How do I identify roads that are dead-ends (no exit)? The 100m part is easy. I know how to use Arc ...
5
votes
2answers
494 views

How can I make segmented roads appear as one line?

I am footling around with Quantum GIS and the British OS Strategi dataset. If I render the roads with a simple line style they look fine: However, if I apply something slightly fancier, it looks ...
2
votes
1answer
572 views

How to design a road with a certain slope

Is there a way that you want to connect two different points of altitude with a constant slope of 7% or another, to draw a line in the 3D model?