Corridor - Conditional Instruction Help for "Node's Horizontal Distance From Node"

I’m trying to get more proficient at corridors instead of doing things manually all of the time. Can someone please help me out with the conditional instruction for “Node’s horizontal distance from node”?


  • Typical road corridor with an adjacent bin wall to the left.
  • I referenced the modelled lines for the swale that lands between the edge of the bin wall and the road into my corridor.
  • The top back of curb is well above the bin wall swale.
  • Classic “varies” notes for the distance and side slope from the curb to the swale.
  • Created a “floating” node, not attached to any materials, using the Slope/Slope instruction that is the intersection of a -4% from the top back of curb and a 5:1 from the swale edge.

What I’m trying to achieve:

  • Maintain a minimum of 1m at a -4% from the top back of curb that I can eventually just connect to the swale edge.
  • If the “floating” node is 1m or more from the top back of curb, connect the the top back of curb to the floating node, then I can eventually connect to the swale edge.

Parts I’m having issues with:

  • Sometime the “floating” node is to the right of the top back of curb based on the 5:1 from the swale edge.
  • I’m most definitely note getting the values for the <> statements right (I feel like I’ve tried ever combination, “-” included since it’s to the left.

Any help would be much appreciated!

So what I am " hearing" is that you are doing the following

From TBC you want a 1m at -4% no matter what

If there is room you will extend that 1m to where it intersects the slope at 5:1 from the swale point

If the 5:1 Slope has insufficient room then it comes up closer than the 1m min and in some cases comes out where you cannot build any of the 1m at all - in this case you just want to connect TBC to swale point or TBC to the 1m point and down to the swale regardless of the slope

So your condition is testing whether your float point is greater than 1m to left of TBC or less than 1m to the left of TBC

If greater than 1m you connect from TBC to float to swale

If less than 1m you so the 1m at -4% then a connect to swale at whatever slope that is.

What happens if your 1m point is left of the swale point? Is that even possible?

Then you are testing the distance between Float and TBC. The calculation is from left point to right point ie if Float - TBC (if Float is -15m from CL) and TBC is 12m from a CL then it is -15 - (-12) = -3 so you want the test to be if the distance is greater than -1000 and less than -1 to create the first test which would then create the connection fromnTBC to Float to Swale. If that fails ie the distance is >-1 and less than +1000 then you do the 1m at -4% and then the connect to swale point

If there is the third scenario where the connect from TBC to Swale is back towards the CL then you would have to have that as a sub condition in the second scenario ie

If the Float is >-1 from TBC then
Check Float against the Swale position and if the value is negative >-1 <0 then connect from TBC to Float to Swale
If >0 <1000 then what do you want to happen ? Nothing or ???

The challenge with this calc is whether the points are to left or right of CL - if to the left then you have to do the double negative = positive equation to determine the offset ranges.

Hope that this helps - if not I can try to build an example tomorrow


That worked out to what I needed, thank you!

Unfortunately, it ended looking like something that was not going to realistically happen in the field based on the elevation of the swale drops along the bin wall. So I ended up just pushing it out the 1m and letting the side slope vary more often.

Thank for the help. It’s a thinker for sure.

True for sure

Glad we could help