Good evening, I have three questions regarding culvert modeling in HY-8. I am relatively new to using this software and am unsure if what I am looking to do is possible. I apologize for my naivety in advance.

1. What is the best way to model a culvert system that has two different barrel sizes connected in series with a 49-degree bend? The culvert system I am working with spans a highway with two 8'x8' barrels on the upstream end that tie into two 10'x8' barrels on the downstream end. The change in barrel size occurs under a grassed median that separates the traffic flow direction. Would I model the two 10'x8' barrels for the design flow first and assign the headwater depth as the tailwater depth for the two 8'x8' barrels? Is it possible to link these sections in series?

2. If the only or best way to model the system described in my first section is to model the two sizes separately, what would be the best way to handle the input for the roadway data (crest length, crest elevation and top width) if the change in barrel size occurs under a location that does not span a roadway?

3. s it possible to model the culvert system in HY-8 with the 49-degree bend mentioned in my first question? If not, how would that condition be handled as an input parameter?

Thank you for in advance for taking the time to read these questions and I appreciate the information, responses and recommendations that anyone will be able to provide.