[pgrouting-dev] Fwd: How to build a web application using pgRouting for solving traffic problem

[Stephen Woodbridge]

On 5/6/2011 3:53 AM, Daniel Kastl wrote:
> Probably this is a good start: http://workshop.pgrouting.org/
>
> <http://workshop.pgrouting.org/>Daniel

Yup, start here and break your project down into a series of steps like:

1. load the data
2. prepare the data
3. get a simple test working with your data
4. look at the list archives for how to generate textual driving 
directions this will require extra work
5. editing the data - all the data is in DB tables so it is accessible 
to changes, but you will need to think through how you want to build a 
application that allows editing of the data - review the prepare data steps

see more inline below ...

> 2011/5/6 Vũ Khắc Tín <tinvukhac at gmail.com <mailto:tinvukhac at gmail.com>>
>
>
>     Dear all,
>     I 'm  a newbie in GIS and pgRounting.I have a problem and can you
>     support for me?
>     I 'm developping a web application.My desire is buiding a web with
>     this functions:

Look at using OpenLayers for a Javascript API for mapping and to build 
your application GUI in. This supports Google but also allows you to 
build an application the is not locked into one vendor.

>     1.Find shortest path in any time( support for traffic problem),
>     "shortest" mean time,cost...

By traffic to you mean getting traffic feeds and dynamically adjusting 
segment speeds? or are you just trying to say your want to solve general 
vehicle routing problems?

>     2.Allow me change data.
>     This is similar google map,but I want to use my data(download from
>     OpenStreetMap),and use pgRoungting to route in that data,then use
>     Google Map API for display the result.

See my order of steps above. You will have to design and build an 
application that interacts with the user making changes and generate 
ajax requests to some server code that updates the database, then 
refresh you screen to the changes from the database.

>     Can you help me? how to use pgRouting in OpenStreetMap data?

There are some tools the support loading OpenStreetMap data into pgRouting:

http://www.google.com/#q=osm2pgrouting

> How to
>     change data? How to return result similarly google?
>     Ex : When I find shortest path in Google Map,they draw path in map
>     and a set of drections:
>                    1.Turn left    A    100m
>                    2.Turn right  B     200m
>                    3.Go ahead   C    300m
>     Can pgRouting do that?

pgRouting does not do this out of the box, but it is possible to do it 
and has been discussed in the list. search the list archives for 
"driving directions". You can look at an example I built here:

http://tinyurl.com/3dz7zbk

Summary, You can do all of this but the project you have outline is very 
big and you need to break it down into smaller pieces that you can focus 
on one at a time. Some of the steps are not supported directly and those 
you will have to write yourself. You will need skills in Javascript, 
Openlayers, postgresql/postgis, pgrouting, and writing ajax handlers (I 
use php for this).

Hope this helps,
   -Steve

>     Thank for read my email !I hope you support me early.
>     PS: Sorry if my English is bad!
>     --
>     Vũ Khắc Tín
>     K53,Department of Software Engineering ,
>     School of Information and Communication Technology,
>     http://soict.hut.edu.vn/
>     Hanoi University of Science and Technology,Vietnam,
>     http://www.hut.edu.vn <http://www.hut.edu.vn/>
>     Email: tinvukhac at gmail.com <mailto:tinvukhac at gmail.com>
>     Y!ID: Xitrum_rapper91
>     Skype: vu.khac.tin
>     Mobile: +84 168 990 4684