If you have half-concurrencies, meh, so be it.
Disagree.
I'd say I agree with Duke87, but what exactly am I agreeing with? What do "you have" and "meh, so be it" mean?
If they
exist in the field, yeah -- so be it. Chin up & accept it, and take reasonable steps to accommodate it if needed. The assumption here is, plotting a 2nd route is not "reasonable steps".
IMO it's better to keep half-concurrencies out
of the data -- more on this below.
Even better example.
Ooh, yes. Very good example.
60, 87 & 287 are all centered between each half of their couplets. As they should be.
Dead center, 87 & 287's route
traces overlap, but the routes themselves don't. One's on the inner roads, the other on the outer.
Did you drive 87 or 287? You may or may not have driven on 60, depending on which direction.
Did you drive on 60? You drove on
something else. Depends which direction.
On a smaller scale, there's where US6 & MA138 cross the bridge into Fall River & link up with MA79.
It was even more confusing back before the MA79 freeway was demolished -- US6 on the frontage rd, MA79 on the mainlines, MA138 on the frontage rd NB & the mainline SB.
Another "maybe you drove something else / maybe not / you drove something else but what was it" scenario.
In both cases I opted to break any concurrencies with hidden points, and let the user decide what they have & have not traveled & enter it manually.