Reverse Cardnality on Divided, Concurrent Routes

08-29-2019 11:31 AM

What do you do?

Let me start this question with the background that while I have been very interested in how other DOT's are defining LRS implementation, now that we have an implementation in production we plan to use for HPMS in 2019, ideas and issues I sort of conceptually grasped are now rocking my world.  Hard.  We are transitioning fully from single carriageway to dual carriageway in this process. This is one issue that has us thinking hard about what to do.

What do you do when there is a route concurrency of a cardinal direction route running opposite directions with a non-cardinal route? 

Here is one of the 18 or so examples in Kansas, US Route 69 cardinal direction is northbound, US 54 cardinal direction is southbound.  By our route dominance rules, we would call the north/south concurrent section US54, which is concurrent with US69 non-cardinal, but the cardinal sections are side by side so fall outside of the capabilities of route dominance processes.  


How do you count/omit mileage in this situation?  (an isolating event or an attribute somewhere?)  Count both sides because they are both primary and cardinal?  

How do you cartographically represent AADT in this situation - the US69 cardinal section is going to look discontinuous?  Events on both routes?

How do you collect pavement in this situation, drive the mainline ramps (which by definition is not a ramp by ftype)? Do you have samples on ramps?  Do you have detail level AADT at ramps and mainline splits?

1 Reply
Occasional Contributor III

We have a few location like this, two that come to mind are both Interstates. I-73/74 in Randolph and Montgomery counties and I-73/85 in Guilford county.

For NC to follow your example US-54 would be the dominate route regardless of direction. All events* in R&H would go on US-54. Only US-54 would be counted for mileage as the dominate route.

AADT is collected wherever/however we represent the route. We only collect AADT on ramps if safe and grade separated.

Pavement is collected wherever/however we represent the route. They are a great resource to make sure we have all routes divided when they should be. If they have no place for the data, they are a unhappy customer. 

Samples, we do not collect samples on ramps. We do have a different route type for ramps. Our HPMS coordinator is out til Oct, but I don't she would collect on a route/ramp flyover in these cases.

*Fed Truck Route/STAA is different but that is story for a different time but we would have Truck Route marked on US-54 if it applied.