[LandXML] Re: Superelevation terminology

  • From: "Banihashemi, Mohamadreza" <Mohamadreza.Banihashemi@xxxxxxxxxxxx>
  • To: <Denis.Schaffer@xxxxxxxxxxx>, <landxml@xxxxxxxxxxxxx>
  • Date: Wed, 19 Jan 2005 11:29:45 -0500

Dear Denis
The superelevation transition stations are coded in the IHSDM software =
as shown below:

end normal cross-slope/begin tangent runout
end tangent runout/begin superelevation runoff
end superelevation runoff/begin full superelevation
end full superelevation/begin superelevation runoff
end superelevation runoff/begin tangent runout
end tangent runout/resume normal cross-slope

If I am not wrong the addition of the "Superelevation" data element was =
started from this. There are some other codes in the IHSDM cross slope =
data that are not needed here. Because the IHSDM codes were too long for =
the LandXML they were abbreviated by Nathan to the current names. =
However, as you suggested changing some of them may make them more self =
explanatory. Another suggestion in this regard could be adding the words =
"entry" and "exit" for runout and runoff stations, where appropriate.

As for the inconsistency between the sample data and the schema, as I =
understand the schema is correct and the sample data is wrong. I suppose =
Nathan is aware of this (as I have informed him some time ago).

regards,
Mohamadreza Banihashemi, Ph.D.
Sr. Transportation Research Engineer
LENDIS Corp.=20
FHWA, TFHRC, GDL, Room T101E (Mail Stop HRDS-05)
6300 Georgetown Pike
McLean, VA 22101
Tel. 202-493-3334
Fax 202-493-3416

-----Original Message-----
From: Denis Schaffer [mailto:Denis.Schaffer@xxxxxxxxxxx]
Sent: Wednesday, January 19, 2005 10:48 AM
To: landxml@xxxxxxxxxxxxx
Subject: [LandXML] Superelevation terminology


I apologize if this has been sent twice, but my first attempt didn't
seem to actually get sent

I realize that it has been there for awhile, but I was wondering where
the terminology for Superelevation stations came from?

Here is what LandXML has, and what I think would make more sense.

BeginRunoutSta - Entering runout location or beginning of super=3D20
BeginRunoffSta - Entering runoff location
FullSuperSta - Beginning of full super (would think that
BeginFullSuperSta would be better)
RunoffSta - End of full super ? (would think that EndFullSuperSta would
be better)
StartofRunoutSta - Exiting runoff location (would think that
EndRunoffSta would be better)
EndofRunoutSta - Exiting runout location or end of super (would think
that EndRunoutSta would be better)

It is just that there is no way to know what these values mean until you
dig into the schema and look at the documentation tags for these
elements.

It is easy to confuse BeginRunoutSta and StartofRunoutSta or
BeginRunoffSta and RunoffSta=3D20


Also, I was looking at the sample data for the Route202Road.xml file.

This is what it has for superelevation points
<BeginRunoutSta>1462.860000</BeginRunoutSta>=3D20
...
<BeginRunoffSta>1512.860000</BeginRunoffSta>=3D20
<RunoffSta>1562.860000</RunoffSta>=3D20
<FullSuperSta>1612.860000</FullSuperSta>=3D20
<FullSuperSta>1931.423243</FullSuperSta>=3D20
<RunoffSta>1981.423243</RunoffSta>=3D20
<StartofRunoutSta>2031.423243</StartofRunoutSta>=3D20
<EndofRunoutSta>2081.423243</EndofRunoutSta>=3D20

The repeated use of <RunoffSta> and <FullSuperSta> do not seem
consistent with the documentation in the schema.

By definition, in the schema, <RunoffSta> is the location where full
super ends on the exiting side of the curve, and <FullSuperSta> is the
beginning of full super at the curve entrance.

Can somebody please explain this?



Denis J. Schaffer
Bentley Systems, Inc.
(256) 774-0269


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