The importance of a naming convention and change control.
I am currently working for John Holland on the upgrade of the Bruce highway between Edmonton and Gordonvale.
The project is currently still in the design phase. One of the tasks I have been involved in so far is conducting a take-off from the Prelim Design drawings to compare this data to the estimates at tender. There are significant differences but identifying them has been more challenging than it should be. Chainages are often a standard point of reference on a road job so how hard could it be? What is the chainage of the top culvert in this picture? What is the chainage of the bottom culvert?
Hint: There are 3x different chainages shown on this drawing.
I know there were mixed views on PMQ but in my mind this is a perfect example of where configuration management and change control would be useful. If every culvert was given a name/number it would save time trying to second guess which chainage different teams had used to refer to which culvert. As it stands the drawings, schedule and programme on this particular project are not as joined up as they should be.
Holdfast Training Services Trial Blog 
Over my Phase 2 and 3 placements I have worked with/for/adjacent to/on top of London Underground, Crossrail, HS2 and Network Rail and the issues are exactly the same (as I guess they are most linear civils projects). LU in particular were a nightmare to deal with as their infrastructure is so old the numbering, referencing and chainage systems all overlap from 100 years of development. Unlike your scenario though, every single thing in the Underground has a number – every door, every handrail, every column, every light switch… – the problem is very few people (if anyone!) know where most of the doors go or what the columns are holding up. If you want a drawing you book into the archives and dig them out yourself in hard copy!
Crossrail on the other hand, having a cleaner slate I suppose, were a bit more organised and spoke a coded language of their own referencing every inch of the new tunnels. While total gibberish to outsiders (i.e. me) this is nevertheless the way to go. Hopefully some of your clashes will resolve in time (before work starts) but I’d think now is the time to get it clear because it will be very tough to recover afterwards.
I am with Tom on this: Nail it down now or there will be hell to pay later. Usual is to define a principle direction and use the chainage in that carriageway to allocate fixed asset numbers. If the asset or alignment move the chainage may become incorrect but the number remains as initialy fixed so it references the asset absolutely but only indicates its approximate location. Interested to know how you resolve it in Aus.