The Man from Down Under
I came across Alex Badaoui’s post a few months ago as I was working remotely in my favorite coffee shop. It has a small pond beside it where I often pace around while thinking through a problem. For several weeks I had been troubled about the conventional method of corridor modeling in OpenRoads. The dreadful loading, the seven different corridor objects, and the over complex templates were throwing me for a loop. I had just begun my largest project yet. The schedule and due dates were very fast paced and almost volatile with how much they changed. As I circled the pond a third time I found myself at a dead end. I could not keep up my models with the constant changes. I searched the web for any sort of help and that’s when I found Alex on Bentley’s online forum.
His post was old. As old as 2017, which to my initial impression, is terribly outdated. Expecting to find poor information, I found something else entirely. He proposed ditching the whole conventional method taught by Bentley and DOTs and suggested something more modular. It was faster, more serviceable, and much more teachable. After a lap around the pond, I sat down and started testing his method with my own project. Let me tell you, after experiencing this large, constantly changing project, I am never going back to the old method.
The feeling of this discovery is hard to describe. I will describe it like this: it was as if I found out I was drinking out of the bottom of a cup the whole time and someone had to show me where my mouth was supposed to go. No wonder there was always a mess around me.
The man I describe is from Australia. Though he has returned to his country, he shared his training materials with me that went into more depth about the method which cleared a lot of things up. I will try to organize all of that into a summary followed by an argument.
A Brief Summary
The 3D Linear Method for corridor modeling breaks a roadway’s components into individual pieces which are all snapped together to a basic controlling template. The basic controlling template is built along the road’s alignment and is assigned the superelevation corridor. Parametric constraints or point controls are used where the road’s width or any other element may change. Individual components like a lane or shoulder are then placed along the alignment and have their ends given point controls to fix themselves to the predetermined points in the basic controlling template. End conditions are then placed along the ends of the road and are free to change as the design requires.
Monoliths & Modularity
A monolithic structure is one large single thing that cannot be reduced into smaller pieces. If one feature needs correcting then the entire structure must be taken down and worked on. A modern smartphone might be like this. You cannot take it apart and replace a single piece. It has to be taken into a shop to be worked on or thrown out entirely and replaced with a whole new smartphone. The conventional corridor is just like this. It is smart like a smartphone. It can have all kinds of corridor objects inside and complex components within its giant template that make certain things appear and disappear depending on all kinds of searching criteria. When it needs to be worked on though, it has to be taken to an expert – usually the initial corridor creator – or it has to be scrapped all together. This is entirely a mess of affairs.
Suppose the initial corridor creator made a very complex template with tons of rules and objects. If they are out of town, sick, or worse, fired, then the rest of the team will have no clue how to modify the corridor within a reasonable amount of time.
It is a sad truth to our industry but most engineers are not tidy with their file naming. This is more apparent when a corridor has 50 objects and they’re all named something incoherent or even all the same name. Good luck to the sorry soul that has to pop the hood open and figure out what belongs to what. Oh and make sure you don’t blow anything else up while you try to fix the one thing. I doubt even the initial engineer will remember what they did after a month off the project. No budget or deadline can be met if this is a regular occurrence.
What I mean to argue is that this method is not survivable in the long run. A project that gets put on hold for a year will have a rude awakening when it gets picked back up again. Now do not think I’m assuming doom on all projects. What I am saying is that the conventional method brings with it many unnecessary risks and headaches.
The 3D Linear Method reduces these by reducing the one large template into bite size pieces. One corridor for each lane, shoulder, curb, sidewalk, end conditions, etc. Each is placed along the mainline alignment and pinned using point controls to an invisible controlling corridor made up of simple points. I will illustrate this in a later post but bear with me here. Here’s an example: you build out the lanes, place the shoulders, and then you drop in the end conditions and then you’re finished. A change comes in to make a portion of shoulder into curb and gutter with some sidewalk behind it. A simple solution is to adjust the shoulder template drop back to where the change begins and drop a new template for a curb and gutter with sidewalk. Modularity is simplicity and the work is much more survivable. If you went with the conventional method, you’d have to make a new master template, scoot back the original template drop to where the change begins, and then drop the new template all with hoping that the end conditions on the other side don’t change, which cannot be guaranteed.
An End for Now
This was a longer post than I originally expected. I can say more but I will have to end it here. I’ll drop a link to Alex’s post here. Read it and consider adopting the idea. It has saved me countless headaches when changes came my way.