To keep two different alignments dynamically linked

[conrado.gallardo]

While designing an exit ramp of a highway, I am trying to keep the first entity of the exit ramp alignment dynamically linked to the highway centerline alignment, so that if any change occurs in the highway centerline the first entity of the exit ramp is always automatically recalculated in order to be tangent to the highway centerline alignment. 

I know that this is a common function in other design softwares.

[conrado.gallardo]

I forgot to say that it may be done with the "Connected Alignment" tool, but the issue is:

- This tool creates a different alignment from the two it connects, which may be useful when calculating intersections but not when designing a highway ramp

- This tool does not allow to include spirals 

[eric_gates_wisdot]

This would be assuming the first entity was a curve or spiral? Or do you also mean a collinear tangent? How would the automatic recalculation happen, meaning what would be the expectation of the second entity of the ramp, or the radius of the curve? Would there be a user parameter interface to define these auto constraints? What happens to the entities if the geometry has no solution? Would defining the constraints be similiar to the Connected Alignment or the dynamic curb return alignments that can be defined through the intersection object/wizard? (just using the geometry portion of the horizontal intersection wizard)

[conrado.gallardo]

My idea would be to include an option within the "Alignment Creation Tools" menu that could be called, for example, "Create Connected Entity". This tool would create an entity for the current alignment that could be of no matter what type of entity (tangent, curve or spiral). When pressing this option, an user parameter interface should arise.

It occurs to me that the user parameter interface may give two options to link the entity to the primary alignment:

- Connect to XXX Sta. of the Primary Alignment.: In this case the calculation would be made in a way that the Connected Entity will always look for the point of tangent in the surrounding of the selected Station.

- Connect to Entity XXX of the Primary Alignment.: In this case the calculation would be made in a way that the Connected Entity will always look for the point of tangent in the selected entity of the Primary Alignment.

In case no solution is found for the selected "Connection" option, an advise message should arise in the alignment that contains the "Connected Entity".

Other options that the abovementioned user parameter interface may have would be, among others, the following:

- Type of connected entity: tangent, spiral or curve with their corresponding parameters when selecting each one of them.

- Overlapping: in case the user wants the current alignment to overlap the Primary Alignment in a certain length.



I hope this clarifies.