How to make chain stations match centerline stations

What software are you using?

But regardless of software, to my way of thinking, the stations on an edge cannot match centreline due to the different lengths of each (unless you have a completely straight road).

Mark Marnell said:

the stations on an edge cannot match centreline due to the different lengths of each (unless you have a completely straight road)

I have run into this on various software packages. It's the fundamental geometry.  if the elements are parallel, and anything other than straight, stationing will not match the whole way along. Any curves to the "inside" are shorter and curves to the "outside" are longer than the curves on the original element. Since they literally are not the same length, they CANNOT match. That's why, in track meets, the runner to the inside of the track starts further back than the runner in the outside lane - to make sure they actually run the same distance.

I ran into this years ago with ditch chains & profiles, when we had the software annotate the station/elevation callouts. The stationing wasn't what we thought it should be, and it took us an embarrassingly long time to figure out why. When we do things manually, we round and adjust and generalize for the sake of simplifying the work. The computer does things precisely, and those things that then "look wrong" are (unfortunately) quite right.

I'll actually be interested to see how this works out as we allow the computers to do so much more of the design, and how it works with the people who read and review plans (and only want to see things a certain way).

Hey Brandon: As has been described already it is not possible to make the stations always match all the time unless the centerline is perfectly straight.  What has not been shared is any sort of potential solution.  

There is not a perfect solution for your situation but there you can improve the correlation of stationing along the edges of pavement by use of equations.  By adding an equation to the stationing of the edge of pavement at the end of every curve, you can synchronize stationing in the tangents. Thru the curved portions there will still be a discrepancy in stationing.  The command you want is Add Equation.

Honestly, adding multiple equations is a bit of a pain and the benefits are limited.  I would not be inclined to do this for my projects, I don't think but it is a potential partial solution for you.  FWIW, this sort of use for equations in common practice in various jurisdictions where divided highways have two baselines, one on each inside edge of pavement..