Reconcile L-line with P-line dialog
This dialog can pop up when you open a Location design. It means that the P-Line traverse (TR1 file) has been shifted, adjusted, shortened or lengthened so that the start and/or end coordinates are different from when the Location was saved.
Transform L-line Coordinates
If the traverse was shifted and/or rotated (no change of shape) then you should pick "Transform L-Line Coordinates" to shift and/or rotate the Location design the same amount. The the transformation parameters are calculated automatically; however, you may use the "Transform..." button to view or change these parameters if desired.
Re-Align to Saved Offsets
If the traverse has been stretched or bent (the shape is different) then you should pick "Re-align to saved offsets". This is what version 3.1 did automatically without prompting. However, this can cause distortion of curves; they will be automatically re-calculated but it is possible that curves will have to be deleted if they no longer fit the tangents..
Do Nothing Now
You can always pick "Do nothing now" and see what happens - it may explain why you got the message in the first place when you see the P-Line and L-Line with no fix. Re-Open without saving to try again using the above choices.
In short, if you move the P-line you must move the Alignment accordingly. Simple transformations (like local to UTM) are safest - just click OK when you see the prompt to accept the default transformation.
What to do after
If you have grossly modified the shape of your P-Line traverse, you will have to adjust your alignment after choosing one of the adjustments discussed above when opening your location design. Some typical examples are discussed here.
P-Line start station changed
If you change the P-Line start station and open an associated Location design, you may not be prompted with the Reconcile L-line with P-line dialog. However, you should be aware that the Module-Setup, Alignment Tab will allow you to also change the L-Line start station.
Segment of P-Line Traverse removed
If you remove a segment of the P-Line Traverse from either end, you must manually delete the alignment in this range. Use the Delete Range dialog.
Segment added to end of P-Line Traverse
If you add a segment of traverse to the end of your P-Line and then open the associated Location design, you will be prompted to "Reconcile L-line with P-line" - choose "Do Nothing Now". Once the design is open, you will see the new P-Line segment in your Plan window.
You may manually create horizontal alignment in the new segment or use Edit-Auto Generate to automatically create Plan alignment points on the new section of P-Line.
Segment added to start of P-Line Traverse
This is almost the same as adding a segment of traverse to the end of your P-Line except that the coordinates of the old start station will change if you are not careful. Re-adjust your P-Line traverse so that the coordinates of the original traverse are the same as they were before, then you can choose "Do Nothing Now" when prompted to "Reconcile L-line with P-line" (this should be true if your traverse is properly geo-referenced).
You may manually create horizontal alignment in the new segment or use Edit-Auto Generate to automatically create Plan alignment points on the new section of P-Line.
Segment of P-Line Traverse modified
If you modify a segment of traverse (for example to implement an alternate route) the unmodified sections of traverse should have the same coordinates. When you are prompted to "Reconcile L-line with P-line" - choose "Do Nothing Now". Once the design is open, you will see the new P-Line segment in your Plan window.
Use Edit-Auto Generate to automatically create Plan alignment points on the modified section of P-Line. Make sure that you choose "Remove Existing" to delete the existing alignment in this area. You will also have to redesign the Vertical alignment and you may wish to use Auto-Generate to similarly remove Profile points.
