Presentation data collection and gtfs

Introduction to Data
Collection & General
Transit Feed
Specification
University of Thessaly,2015
GreenYourMove Project
With the contribution of the LIFE programme of the European Union - LIFE14 ENV/GR/000611

Contents of this presentation
 Definitions and Terminology of:
 Stop, Routes, Trips, Layers/Shapefiles, CRS, layer features, csv files
 OpenStreetMap
 General Transit Feed Specification(GTFS)
 QuantumGIS(QGIS) & OpenLayers Plugin
 PostgreSQL, PostGIS & Shapefile and DBF Loader Exporter
 shp2GTFS
 Basic usage of:
 QGIS
 PostgreSQL & PostGIS
 shp2GTFS
 Conclusion and final results
4

Definitions and Terminology
 Stop: An object that is defined by a geographic point on Earth and a name/ID, and is usually
served/contained in public transit route.
 Route: A sequence of stops that are served by a specific vehicle one after another. Information
in a route are geospatial objects with IDs and are time-independent .
 Trips: Trips are time-dependent executions of routes and they are grouped according to which
route they belong to.
 Layer/Shapefile: These are two concepts that are interconnected. A shapefile is a data format
for GIS systems, which describes vector features, such as points, lines and polygons. When they
are used in QGIS they are represented as layers on the map.
 CRS: Coordinate Reference System is a system used to locate geographical entities. We will
mostly use WGS84 and WGS84/Pseudo Mercator.
 QGIS: In QGIS we will create layers, which will contain points and lines and fall under the
generic category of layer features.
 CSV file: Means Comma-Seperated Values file and is a text file in which every line represents a
data record. Each record consists of one or more fields, seperated by commas.
5

OpenStreetMap – website https://www.openstreetmap.org/
Definition: As stated on their website: “OpenStreetMap is a free geographic data.
OpenStreetMap built by volunteers largely from scratch and released with an
open-content license.”
Why do we need it?
It provides us with datasets about the road network. In most of the cases the raw
data from OpenStreetMap needs to be edited in some way in order to use in an
application.
6

General Transit Feed Specification(GTFS) – website
https://developers.google.com/transit/gtfs/
Definition: As stated on their website: “The General Transit Feed Specification
(GTFS) defines a common format for public transportation schedules and
associated geographic information.”
Why do we need it?
Because it will be the data format we will use to represent the transit network. It is
the mainstream approach when it comes to schedule-based datasets. Its
development is supported by big organizations and the number of data available
in this form is really bigger than in any other form.
7

QuantumGIS(QGIS) – website http://www.qgis.org/
Definition: It is an open-source Geographic Information System(GIS) that is used
for viewing, editing and analyzing geographic data.
Why do we need it?
We use QGIS for data collection. By exploiting the schedule-based nature of a
transit network, we create layers which contain all the geographical information of
a route. Taking for granted that we somehow know the longitude, latitude and id
of a station in a route, we can create a layer containing stops of a route. Next, we
use QGIS to create another layer with the data of the actual path the vehicle
follows. The output file format are shapefiles. When we open shapefiles with a GIS
system they are represented as layers.
8

PostgreSQL, PostGIS & Shapefile and DBF Loader Exporter -
http://www.postgresql.org/ , http://postgis.net/
Definition: PostgreSQL is an open-source, object-relational database system, while
PostGIS is an extension for that database which adds support for geographic
objects and allows to run queries for geographic related content in SQL. DBF
Loader Exporter is a simple tool for loading files into the database.
Why do we need them?
It is where we store our data. Furthermore, it allows to run queries to analyze and
edit our data. In combination with Python’s modules they are the two main tools
that we used in our script shp2GTFS.
9

shp2GTFS – not available on website yet.
Definition: It is a Python-based script we created that enables us to
transform shapefiles to a GTFS feed with less effort than any suggested
approach that we are aware of.
Why do we need it?
Because we need to convert the data we gathered with QGIS to GTFS
feeds. There were no tools available online that would enable us to
combine the simplicity of gathering data with QGIS and transform the
produced layers/shapefiles to a GTFS feed.
10

Basic Usage - QGIS
11
The interface:
Basic Toolbar, contains
most of the tools we
need
and will use
In this box we can see the layers have opened on our canvas.
Lon,Lat & CRS information
Canvas

Basic Usage - QGIS
From the basic toolbar we will need:
12
Add feature
(Point or Line)
Used to open a map
layer(plugin)
Select and deselect a
feature

Basic Usage - QGIS
About the Plugin and the creation of a layer
13

Basic Usage - QGIS
Note that:
 When we create and save a shapefile to a folder in our computer, there
are several files created with it. We only care about the shapefile, but
we want to keep the other files too, because they contain information
about CRS, encoding, etc. Opening and editing the shapefile only is
enough and other files change accordingly.
 We are always have to open and work on a OpenStreetMap map layer
and not use other services like Bing Maps or Google Maps.
14

Basic Usage – PostgreSQL - PostGIS
We use the software through a graphic user interface called pgAdmin 3.
15
pgAdmin’s icon:

16
In order to load files onto the
Database we use the a plugin:
After entering username, password
and database name we can connect
and load shapefiles onto the database.

*Note that:
When installing the database software we enter username and password.
We used same username and password for all of the PCs we used.
Also before using the loader software you should add to “Path” System
Variable the path to the location of the “bin” folder in Postgres’s
installation folder.
(The path on my computer is: C:Program FilesPostgreSQL9.3bin )
17

Basic Usage – shp2GTFS
shp2GTFS is a tool we created and is still in development phase. Its usage
is based around the keyfiles. Keyfiles are csv files that contain
information about the timetable of the trips and other logic that needs to
be included in a GTFS feed.
Actually, it connects to the database using a python module, retrieves the
data we ask it to retrieve, and combining them with the information on the
keyfiles it produces the GTFS files one by one.
18

Basic Usage – shp2GTFS
*Note that:
Using shp2GTFS is achievable through Windows Command Prompt and
Cygwin.
Before using shp2GTFS you should set System Variable “client_encoding”
to “UTF-8”.
All input and output paths in the script need to be changed before using it
on another computer or you need to have the exact same folder setup on
all computers.
19

Thank you for your attention!
For more information on our project, visit:
http://www.greenyourmove.org/
Or contact us at:
dimrizopoulos@gmail.com
saharidis@gmail.com
info@greenyourmove.eu
20

Presentation data collection and gtfs

More Related Content

What's hot (20)

Similar to Presentation data collection and gtfs (20)

More from LIFE GreenYourMove (17)

Recently uploaded (20)

Presentation data collection and gtfs