Numbering schemes for county highways/roads

[jbnv]

I'm working on a renumbering/reorganization/turnback proposal for the Louisiana state highway system. In my proposal, many highways that the state does not retain will become "parish highways." My idea is that LaDOTD will provide guidance and a small amount of money to the parishes, so that the "parish highways" form a secondary system that feeds into and supplements the now-smaller state highway system. I am contemplating two possible schemes for numbering these highways.

My original idea was to give them letters a la Wisconsin.

Then I decided to give them numerical designations based on the function of the roads and the highways from which they "branch." A route that spurs or branches from a state highway would receive the number of that highway plus a letter suffix (e.g. "1D," "28A"). Other routes would keep the original number or take a new number that isn't used by a state highway in the parish.

I see pros and cons in both approaches. Letters alone are simple, but don't always give navigational information. Suffixed numbers can give navigational info, but can also result in clusters of nearby routes with the same number but different suffixes. (One example: My proposal has four highways numbered 16--the state highway and three alternates--in a three-mile stretch near Denham Springs.)

What are your thoughts?

(I'm not quite ready to share the site where I'm building my proposal, but hopefully will be ready shortly.)

[Alps]

West Virginia's fractional routes are essentially the same as your number plus suffix. I would just give them letters.

[Urban Prairie Schooner]

I'm working on a renumbering/reorganization/turnback proposal for the Louisiana state highway system. In my proposal, many highways that the state does not retain will become "parish highways." My idea is that LaDOTD will provide guidance and a small amount of money to the parishes, so that the "parish highways" form a secondary system that feeds into and supplements the now-smaller state highway system. I am contemplating two possible schemes for numbering these highways.

My original idea was to give them letters a la Wisconsin.

Then I decided to give them numerical designations based on the function of the roads and the highways from which they "branch." A route that spurs or branches from a state highway would receive the number of that highway plus a letter suffix (e.g. "1D," "28A"). Other routes would keep the original number or take a new number that isn't used by a state highway in the parish.

I see pros and cons in both approaches. Letters alone are simple, but don't always give navigational information. Suffixed numbers can give navigational info, but can also result in clusters of nearby routes with the same number but different suffixes. (One example: My proposal has four highways numbered 16--the state highway and three alternates--in a three-mile stretch near Denham Springs.)

What are your thoughts?

(I'm not quite ready to share the site where I'm building my proposal, but hopefully will be ready shortly.)

Your idea sounds like what the state used to do in the pre-1955 era when sections of road were bypassed - the old section received an alphanumeric designation (7-D, etc.)

Multiple routes with the same numeric prefix in a short space, as you mention above, would indeed be confusing. Numbers arranged in a grid system (if doable) would be better. (Baldwin County, AL is the inspiration for this concept.) Of course many of the existing parish road networks don't lend themselves too well to this (La. isn't the Midwest), but at least with numbers you have the advantage of unlimited values, as opposed to letters which are restricted to twenty-six characters (or fewer if you are excluding I and O due to similarity with 1 and 0, etc.). Knowing the number of roads that should be turned back, I can imagine this would fall short when dealing with long "parent" routes such as LA 1 or LA 16.

Another idea is to use the standard Iowa county route numbering system, as explained here: http://iowahighways.home.mchsi.com/highways/countyrd.html. (I think this may also be used in a few other states.) Of course this introduces letters again, but the letter comes first in this case and would give you some idea of what part of the state you are in; also these combinations can be repeated along a line of latitude/longitude if necessary.

The parish maintained routes can be ultimately divided into two classes - "parish highways" which are roads already under local control and former state highways of really minor consequence, and "parish state-aid highways" which would be comprised almost entirely of the more important former state routes, usually with a functional class of rural collector at minimum. Only the second category would be eligible for state aid.

In an "ideal" system, this second category would also include the routes which the state wishes to keep in rural areas per the LADOTD turnback maps, but really do not function as important routes. They could remain as state routes until such time as it is decided to formally transfer them to the parish state aid system.

Looking forward to seeing your turnback ideas. Will be interesting to compare to mine and others.

[jbnv]

The parish maintained routes can be ultimately divided into two classes - "parish highways" which are roads already under local control and former state highways of really minor consequence, and "parish state-aid highways" which would be comprised almost entirely of the more important former state routes, usually with a functional class of rural collector at minimum. Only the second category would be eligible for state aid.

This is basically what I am proposing, and why I'm maintaining a distinction between the existing parish roads and the demoted state highways. Several parishes still use the pentagon signs, so I'm introducing new signs for these roads as well (the rounded rectangles that I posted in other threads).

After reading the Iowa article, I proposed to reuse a system from early in this project: A letter prefix and one or two digits, with these meanings:

Sxx: A spur from a major highway to a destination.
Bxx: A business route into a community.
Lxx: A loop or bypass around a community.
Axx: An alternate route to a major road.
Pxx: A parallel route of a major road. (For cases where the route is not a suitable alternative.)
Cxx: A connector between two routes or crossing over a waterway.
Rxx: A rural route with no useful association with other highways.

My first attempt at renumbering the highways actually used the number of the parent highway AND the letter-number suffix. This produced a utilitarian but hideous numbering system.

[SD Mapman]

The parish maintained routes can be ultimately divided into two classes - "parish highways" which are roads already under local control and former state highways of really minor consequence, and "parish state-aid highways" which would be comprised almost entirely of the more important former state routes, usually with a functional class of rural collector at minimum. Only the second category would be eligible for state aid.

This is basically what I am proposing, and why I'm maintaining a distinction between the existing parish roads and the demoted state highways. Several parishes still use the pentagon signs, so I'm introducing new signs for these roads as well (the rounded rectangles that I posted in other threads).

After reading the Iowa article, I proposed to reuse a system from early in this project: A letter prefix and one or two digits, with these meanings:

Sxx: A spur from a major highway to a destination.
Bxx: A business route into a community.
Lxx: A loop or bypass around a community.
Axx: An alternate route to a major road.
Pxx: A parallel route of a major road. (For cases where the route is not a suitable alternative.)
Cxx: A connector between two routes or crossing over a waterway.
Rxx: A rural route with no useful association with other highways.

My first attempt at renumbering the highways actually used the number of the parent highway AND the letter-number suffix. This produced a utilitarian but hideous numbering system.

If this was standardized and signed everywhere, life would be easier.

[jbnv]

I'm adding another group: Wxx, for roads that run along a river or waterway. Several Louisiana state highways run alongside waterways.

[froggie]

For simplicity, I'd just devolve them to numerical parish routes.  Minnesota does this without much of an issue.  Given that some Lousiana parishes already have such, it's not that much of a stretch to add routes that LADOTD turned back (also something that often happens in Minnesota).

The painful part will be for those parishes that don't already have a parish route system.

[jbnv]

The painful part will be for those parishes that don't already have a parish route system.

My rollback plan gives them one, already numbered and logically tied to the remaining state highway system.