transport model

[ahmadhasan]

hello everybody
i am new in transportation field but i have a good experience in gis and development and building geodatabase
i have some question how to apply data in ministry of transportation to work with transportation model
i read the documentation related to this model but i did not understand
also i read some article about linear reference system
i need some explanation and step by step how to prepare the ministry data to work with transportation model
from centerline, segment ,nodes,...etc

[JoshuaDamron]

Ahmad,
  The question you are asking is very broad ("How do I make a model work"). 

If you could break down your question to more clearly show the problems you are having, what you have tried, why it is not working and the goals you are trying to achieve, etc. it would help others to answer your question.

All the best,

Joshua

[ahmadhasan]

when i came to ministry i seen that they work in old system , this system  in oracle tables not based on gis solution
there are many tables describe road network like
nodes - start node ,stop node
links
alignment

our department responsible of entry new roads or update roads (split,extent,delete ....etc)

and if there is new road to entry the user fill oracle form then when he want to apply the location he go to arc and figure the location then he back to oracle form and enter x and  y


so finally i have a data and i want to work in standard environment
and as i see the transport model is Good one
so relay i don't know from where to start and if i apply this model in the ministry how the update strategy will be

[AdrienLitton]

Ahmad,

Implementing a transportation data model is no small undertaking.  The reason I think you're having trouble knowing where to start is that both the model and the implementation are extremely complex.  Factor that into the organizational issues surrounding displacing a strictly RDBMS based solution with a more geocentric maintenance approach and you can have what seems an impossible task. 

The first thing to do (if you haven't already done so) is visit our Roads and Highways Resource Center at http://resources.arcgis.com/content/roads-highways/about.  This will point you to a number of links that can provide more information on our Transportation Model, including a sample download that comes complete with a sample migration plan.  The data migration plan includes a description of the steps required to migrate data from an existing system to the geodatabase.

This may give you just what you need to get you started.  If it doesn't, don't hesitate to contact your Esri account manager or international distributor to connect with Esri Professional Services or access our extensive network of business partners who can steer you in the right direciton or provide you a quote for any specific services you might need.

[AdamCabrera]

Within this model, how do I translate between multiple LRM's?  Every time I think I have it, I lose it.  It seems to me that the LRMPosition table is the key, but what exactly should be stored there?

[AdrienLitton]

To use the LRMPostion table to translate between LRMs you must first locate your event data in one LRM and then translate that XY location to other LRMs.  There are a number of ways to accomplish this, but here's the basic process:

1. Create calibration points for each LRM - you must have, at a minimum, a calibration point at the ends of each contiguous part of each route.

2. Generate publication routes by joining Route, SegmentSequence, Segment and Centerline and then calibrating the result (it's easier if your Centerline is polyline-M to start).  You'll want one route layer for every LRM.

3. Transform your event table across your LRMs.  It is assumed that your event table initially had measure values (1 for point events, 2 for line events) for a base LRM.  Now you want to translate these across all LRMs.

4. Populate the LRMPosition table with the results of each transformation and use the results table to populate the 1:M relationship between event and LRMPosition.  In this way you can separate your business data from its location information and store only business information in the event table.

5. To switch between LRMs, join the event table to the LRMPosition table based on the LRMType.  One event may have many LRMPositions, but only one per LRM.

I realize this seems a bit convoluted and difficult to manage.  We are in the process of developing a highway data management solution product due out in December 2011 that will, among other things, handle the translation between LRMs for you.  See our white paper at http://www.esri.com/library/whitepapers/pdfs/highway-data-management.pdf for more information.

[AdamCabrera]

Adrein,

Thanks this information is very helpful.  A couple of additional questions:

1.  In the LRM Position table multiple records can have the same LRMPositionID:
3295   StateMileLog...
3295   LocalAddress...

How are these positions uniquely identified?  In the Highway Data Model, the only ID's are the LRMPositionID and the RoadwayID.  Would I use the GeoPositionID in the GeoPosition Table?


2.  Where does the LRMPositionID come from, or where is it generated?

-Adam