Highway Classification Abbreviations

[Brian556]

In Texas they are as follows:
IH-Interstate Highway (TxDOT uses "IH"; most cities use "I" )
US-US Highway
SH-State Highway
FM-Farm To Market Road ("FR" was formerly used, have seen it on a few old signs)

TxDOT uses the "IH" on it's signal-mounted street name signs. I think the reason is that on TxDOT doccuments there is a two-letter classification of each highway type.

Does any other state use "IH"?
In Texas, State highways are "SH". What, if any, other states use "SH" vs "SR"

Concerning the "FR", I saw that abbreviation on a "LOAD ZONED BRIDGE XX MILES AHEAD..." sign that we replaced in the mid 2000's. I also saw it on a few on Krum's street name blades. I think those don't exixt anymore

[myosh_tino]

IINM, Caltrans does not differentiate between highway types and calls all numbered highways "Route XX".  The reason why Caltrans can get away with this is because route numbers regardless of type cannot be duplicated.  In other words, there cannot be a CA-180 and an I-180 unless it's the same route (i.e. I-15/CA-15 in San Diego and I-110/CA-110 in Los Angeles).

[Brandon]

IINM, Caltrans does not differentiate between highway types and calls all numbered highways "Route XX".  The reason why Caltrans can get away with this is because route numbers regardless of type cannot be duplicated.  In other words, there cannot be a CA-180 and an I-180 unless it's the same route (i.e. I-15/CA-15 in San Diego and I-110/CA-110 in Los Angeles).

Sounds like Wisconsin where everything is "Hwy" this or that.

Now, Illinois is a bit odd, if you will.  Of course, there's the I-xx for interstate, US Rte xx for a US route, and ILL Rte for an Illinois state route on the green signs and street blades, but if you look closely at the bridge plaques and other such markers, there is a variety of abbreviations.

SBI - State Bond Issue Route
FAP - Federal Aid Primary Route
FAI - Federal Aid Interstate Route
FAS - Federal Aid Secondary Route
HB - House Bill Route
SB - Senate Bill Route
OR - Other Road - financed through other means
CO - County Road - County highway part of the state network

And, no, the numbers do not necessarily match up with the marked route numbers.  However, that said, more than a few of the original SBI routes still carry their numbers since they were approved and assigned in the 1910s and 1920s.

[Duke87]

New York just calls everything a "route" (although there is a terminology distinction between signed "touring routes" and unsigned "reference routes") - although, number duplication is possible because interstate highways all internally have the suffix I (I-88 in New York is New York route 88I).

Connecticut uses SR for signed routes and SSR ("state service road") for unsigned routes. But there is no number duplication between the two.

[NE2]

New York just calls everything a "route" (although there is a terminology distinction between signed "touring routes" and unsigned "reference routes") - although, number duplication is possible because interstate highways all internally have the suffix I (I-88 in New York is New York route 88I).

Don't forget about the state highway (SH) numbers assigned to everything state-maintained, mostly numbered in order of takeover.

[kphoger]

I got a speeding ticket in Kansas once on which the officer called U.S. Hwy 400 "U-400".

Minnesota seems to like to call all county highways "CSAH" even if the one in question isn't, in fact, a state aid highway.

[BlueNacho]

CO - County Road - County highway part of the state network

How can a county highway be a part of the state highway network? Doesn't IDOT only sign highways they maintain/fund?

[Kacie Jane]

Similar to California, in Washington everything is technically an SR, although the typical I-x and US x abbreviations are also seen.

[Takumi]

In Virginia interstates and US routes have the standard "I-X" and "US X" abbreviations. VDOT refers to both state primary and secondary routes as "route X" in documents. Chesterfield uses "SRX" (no space) on its blade signs for both. I (and other Virginia people on here) usually use "VA X" for primary routes and "SR X" for secondaries.

(Edited to say which state I was talking about)

[corco]

Wyoming goes
I-xx
U.S. xx
WYO xx
in pretty much everything-  I think I've seen Hwy used instead of WYO, but very,very rarely. Usually all VMSes, documentation, and printed sources read WYO

Internally, every single street and highway- city, county, and state has an ML- "Main Line" number that is used- this often corresponds with the highway- I-80 is ML80. Then there are a few other designations (OT- Optional Turn, RP- Ramp, and a couple other really rare ones) - I actually had a hand in verifying/designating the numbers for the city streets a couple years ago. To my knowledge there is only one place where this system pops up in the field-on an erroneous bridge inventory sign on WYO 313.

Mileposting is based off the ML number, though, not the highway number. The ML mileage often correlates with the expected highway number mileage, but not always- the independent parts of US-26 through the state come to mind as an example. Then sometimes the ML travels with a different highway- so 287/789 north out of Rawlins has an ML, and then that ML follows WYO 220 east to Casper, with 287/789 getting a different one, starting at 0 again at the 220 junction. It's sort of similar to the Oregon highway/route system in that aspect. 

[TheStranger]

I got a speeding ticket in Kansas once on which the officer called U.S. Hwy 400 "U-400".

Kansas calls their state highways K-XX (i.e. K-10 for the South Lawrence Trafficway), similar to Michigan's M-xx (which came about with the M markings in the state route shield).

[PAHighways]

Officially PennDOT and PTC roadways are known as SR (State Route) ####, but unofficially everything is referred to as Route #### for US, PA, and the quadrant routes, and I- for Interstates.

TR used to mean "Traffic Route" to refer to the posted route number when the Legislative Route system existed, but now TR, or usually just T-, refer to Township Route ###.

[J N Winkler]

I got a speeding ticket in Kansas once on which the officer called U.S. Hwy 400 "U-400".

Kansas calls their state highways K-XX (i.e. K-10 for the South Lawrence Trafficway), similar to Michigan's M-xx (which came about with the M markings in the state route shield).

In some contexts (e.g. camera tour drop menus on 511 sites), KDOT tries to get route type designator down to one letter, which forces "U-" for parity with "K-" and "I-."  The long form of the project number as used in letting results summaries also uses one letter (without hyphen) for the type designator, and zero fills to bring route number and county up to three digits each.  (Type designator and zero fills are omitted in ordinary use.)  KDOT's current record-holder for most expensive construction contract ($91 million) has the project number I435‑046 K 8262‑01 as listed in letting results:

*  "I" for Interstate

*  "435" for I-435

*  "046" for County 46 (Johnson County) (Kansas has 105 counties and the numbers are assigned alphabetically; "106" is used for projects which extend into multiple counties)

*  "K" as the jurisdiction identifier (in this case, KDOT-maintained infrastructure) ("KA" extends the "K" series since KDOT has run out of number groups for "K" alone) (cities and counties can by agreement carry out "K" projects, and the City of Wichita has done this for recent Kellogg interchange projects)

*  "8262" as a macro number for a group of related projects dealing with I-435 in Johnson County

*  "-01" as a specific project within the macro group

It varies, but when a planned improvement of large scope is divided into multiple projects as the project development process unfolds, preliminary engineering and design tend to be attributed to an "-01" project while the subsequent projects for actual construction are assigned higher two-digit numbers.  For example, the K-18 freeway upgrade just west of Manhattan had preliminary stuff on project number 18-81 KA-0410-01 while the actual construction contracts were assigned numbers 18-81 KA-0410-03 through -05.

On actual signs, KDOT doesn't try to do "U-400" for US 400 but does tend to hyphenate US route designations--e.g. "US-283."

[roadfro]

Nevada DOT uses the following designations for signing purposes.

Interstate: I-##
U.S. Route: US ##
State Route: SR ##
(US and state routes are sometimes hyphenated on signs when displayed as text, it's inconsistent.)


In the state maintained routes book, NDOT's internal terminology is slightly different:

Interstate: IR##
U.S. Route: US##
State Route: SR##
Frontage Road: FRxx## (where "xx" is the two-letter county abbreviation used on mileposts).

FR's are unsigned, but may have mileposts. Access Roads (AR), State Park Roads (SP) and rest areas/rest parks (and the roads within, where applicable) (RP), are identified similarly to frontage roads.

[surferdude]

Officially PennDOT and PTC roadways are known as SR (State Route) ####, but unofficially everything is referred to as Route #### for US, PA, and the quadrant routes, and I- for Interstates.

TR used to mean "Traffic Route" to refer to the posted route number when the Legislative Route system existed, but now TR, or usually just T-, refer to Township Route ###.

Also according the RMS (Roadway Management System),

State Routes (SR's) are identified by four-digit numbers. SR numbers are assigned as follows:
1. Traffic Routes: Routes designated as Interstates, US or PA Routes 0001-0999
2. Quadrant Routes (Non-Traffic Routes) 1001-4999
3. Relocated Traffic Routes 6000-6999
4. Turned Back, Abandoned, or Null Routes 7000-7999
5. Interchanges 8001-8999
6. WYE's 9101-9199
7. Rest Areas 9201-9299
8. Truck Escape Ramps 9301-9399
9. Others 9401-9499

[agentsteel53]

6. WYE's 9101-9199

what is a WYE?

[Scott5114]

A wye is a Y-shaped junction, like OK-58 at OK-152 (too sleepy to do a Google Maps link at the moment). Basically instead of a standard T three way junction, the stem of the T forks to the left and the right, forming a Y, with a large triangular island in the middle. Both forks of the Y permit two way traffic. I don't really know why some junctions are wyes and some are T's...

[agentsteel53]

A wye is a Y-shaped junction, like OK-58 at OK-152 (too sleepy to do a Google Maps link at the moment). Basically instead of a standard T three way junction, the stem of the T forks to the left and the right, forming a Y, with a large triangular island in the middle. Both forks of the Y permit two way traffic. I don't really know why some junctions are wyes and some are T's...

so are there TEEs, or just T's?

[Kacie Jane]

A wye is a Y-shaped junction, like OK-58 at OK-152 (too sleepy to do a Google Maps link at the moment). Basically instead of a standard T three way junction, the stem of the T forks to the left and the right, forming a Y, with a large triangular island in the middle. Both forks of the Y permit two way traffic. I don't really know why some junctions are wyes and some are T's...

A wye example from old US 99 near Arlington, WA.
http://maps.google.com/maps?q=arlington,+wa&ll=48.186919,-122.193031&spn=0.003813,0.010568&oe=utf-8&client=firefox-a&hnear=Arlington,+Snohomish,+Washington&gl=us&t=h&z=17&vpsrc=6

[corco]

I don't know about TEEs, but there is a Why, Arizona - named after the wye intersection that used to sit there

[Takumi]

Virginia usually designates one part of the wye where two primary routes meet as the ending/turning route with a Y suffix, such as VA 6Y and VA 54Y. It also uses the Y designation in place of the SPUR designation at T intersections, such as VA 300Y in Powhatan.

[PAHighways]

Officially PennDOT and PTC roadways are known as SR (State Route) ####, but unofficially everything is referred to as Route #### for US, PA, and the quadrant routes, and I- for Interstates.

TR used to mean "Traffic Route" to refer to the posted route number when the Legislative Route system existed, but now TR, or usually just T-, refer to Township Route ###.

Also according the RMS (Roadway Management System),

State Routes (SR's) are identified by four-digit numbers. SR numbers are assigned as follows:
1. Traffic Routes: Routes designated as Interstates, US or PA Routes 0001-0999
2. Quadrant Routes (Non-Traffic Routes) 1001-4999
3. Relocated Traffic Routes 6000-6999
4. Turned Back, Abandoned, or Null Routes 7000-7999
5. Interchanges 8001-8999
6. WYE's 9101-9199
7. Rest Areas 9201-9299
8. Truck Escape Ramps 9301-9399
9. Others 9401-9499

Got the whole rundown here.

[vdeane]

New York just calls everything a "route" (although there is a terminology distinction between signed "touring routes" and unsigned "reference routes") - although, number duplication is possible because interstate highways all internally have the suffix I (I-88 in New York is New York route 88I).

On reference markers that is true, but on their internal route log I is used for interstates, US for US routes, and NY for state routes.  Not that that stops locals from just calling everything "route x".

https://www.dot.ny.gov/portal/page/portal/divisions/engineering/technical-services/highway-data-services/traffic-data

[surferdude]

According to PennDOT RMS Manual it states a why is:


Wye's
A wye is a roadway that aids traffic flow at an at-grade intersection (Figure 2-11). A wye is separated
from the mainline by some type of median, and must be at least 200 feet in length. If the length is
less than 200 feet, then the roadway is to be designated as a connector (also referred to as a "leg" ).
Separate wye's located at the same at-grade intersection are typically designated with different SR
numbers. Wye's are commonly given even SR numbers if the connecting SR is even numbered, or if
the wye branches off the Northbound or Eastbound direction of a divided SR. Odd SR numbers are assigned if the connecting SR is odd numbered, or if the wye branches off the Southbound or the
Westbound direction of a divided SR.

It also has a picture but I am not sure how to attach it?

[PAHighways]

SR 9104 in Westmoreland County

That road carries PA 66 northbound traffic, but the main alignment of 66 is considered coming to the T-intersection then turning left and SR 0356 beginning there (heading away from the picture).