INDOT’s Reference Post System

In 1999, the Indiana Department of Transportation decided that it was time to come up with a system that would help better keep track of features along the roads that for which it was responsible. While is would be based, according to INDOT, on the mileage of the road, it was not a milepost system. It was a locator for maintenance items, other than signs, on the state highway system.

RPS 86 on US 40, Marion County, Indiana (Washington Park Cemetery). From Google Maps, snipped 23 December 2020.

There are many parts to the system. The one that most people would have seen, but not really noticed, were the signs that were put up for use with the system. These consisted of small blue signs with a mile number on it, with a smaller sign, if needed, below it with an offset to that mile on it. The signs themselves were barely wider than the post they were on. Very small in relation to most highway signs. Since they are technically only for INDOT use, their size wasn’t a concern. The public wouldn’t notice them, lessening the sign pollution that departments of transportation have been trying to keep under control forever.

RP 88, Offset .88, US 40 bridge of Buck Creek, Cumberland

I really wish I could have had a better snippet for the offset post, but then, the idea was to give the reader the image of what they roughly look like, so the reader would know what to look for.

The RPS manual is very detailed in its information. For instance, the picture to the left is listed as “RP_U_40_Post_86,” meaning “Reference Post, US 40, Post 86.” The one on the right is listed as “CUMBERLAND CORP. LINE BR 4588 O BUCK CREEK,” at least in the 2004 manual.

US 40 is a very prime example of why this system isn’t to be used as a mileage post system. The system was setup prior to the 1 July 1999 decommissioning of US 31, SR 37 and US 40 inside the Interstate 465 loop. What was, in 1999, marked as mile 86 on US 40 is, in 2020, at mile 92.37 on that very same road in 2004. In 2016, the last update from INDOT, it was listed as US 40 mile 65.179. The legal definition of US 40 was lengthened when it was rerouted along the southside of Indianapolis on I-465 in 2004. By a little over six miles. By 2016, the extra mileage along I-465 was removed to show a more accurate road mileage count towards INDOT’s limit of 12,000 miles.

But there is a bit more to the reference post system that comes into play. Each highway listed in the RPS not only includes the complete mileage for the road in Indiana, but they are also listed by the mileage per county, as well. For instance, reference post 86 above is listed as Marion County mile 24.06 in 2004. In the 2016 manual, that mileage is 5.027.

Then, the reference post system records almost everything along the road. This includes EVERY village/town/city street that intersects with the posted road. For instance, near reference post 86 is, in the 2004 manual, “86 + 0.21 24.52 IR 4193 LT (DELBRICK LN).” At reference post location 86.21, 24.52 route miles into Marion County, Delbrick Lane connects to Washington Street (US 40) on the left (north) side of the road. Directions are listed from the increasing number of the reference post. Every street is listed, although almost none of them have a reference post sign.

Also, the corporation limits of towns and cities are listed by the reference post location, although there is no reference post installed most of the time. This even includes old corporation limits. For instance, in the 2016 manual, reference post 85+0.686 is listed as “City or Town Limit – Indianapolis.” Post Road is reference post 86+0.668. Legally, Indianapolis continues for another at least two miles (the sign welcoming one to Indianapolis is west of German Church Road, the county line is another mile east of that, but that is in the town of Cumberland. And even legally, Cumberland is part of Indianapolis. It is as confusing as all get out, but suffice it to say, for the past 50 years, the city limits of Indianapolis have been the county limits of Marion County, with some exceptions. Certainly not Post Road.

But the idea of the legal multiplex of I-465 with almost every INDOT road in Marion County (there are two that don’t mix with I-465: US 136 and SR 135) that brings up another question. What about multiplexes of state roads?

When the system was created in 1999, it was designed with a hierarchy of roads. That hierarchy was interstate, US highway, then state road, in that order. INDOT does not use the term “multiplex” officially. It is called “travel over” in Indiana. The following picture comes from the INDOT RPS guide of 1999 showing how “travel overs” are handled when it comes to marking the mileage of the road.

Indiana Department of Transportation Reference Post System Users Guide, May 1999.

As you can see, near Frankfort, US 421 takes precedence with the little blue signs. SR 39 is junior to SR 38 when it comes to the signs, only due to the fact that 38 is before 39 numerically.

The system underwent some changes between 2004 and 2015. In 2015, it was made perfectly clear that the manual may contain some mistakes, but that every effort was taken to avoid them.

There was also a special note involving US 40 in Vigo County. When US 40 was removed from most of Vigo County, and rerouted along I-70 and SR 46, the RPS system was not changed to reflect that. The section of US 40 that “travels over” SR 46 is still labelled as SR 46. Here is INDOT’s explanation: “US 40 in Vigo County has a special issue that needs to be addressed. Due to relinquishments and creating a travel over for US 40, the alignment does not follow the historic path. US 40 now traverses where SR 46 has traditionally been and SR 46 is considered the Travel Over on US 40. However, the existing reference posts are still for the SR 46 route and are running in a contrary direction to the increasing direction of US 40. Therefore, for the purposes of this book, RP and Offset for the first 3 miles of US are based on the State Log Measure until it reaches the traditional location for US 40 and then jumps to RP 11 + 00 at the intersection of SR 46 and US 40.”

I mentioned above about the original system being put in place prior to the decommissioning of routes in Marion County. It is important to note that there were more routes affected than just those that were moved to I-465. Those routes were US 31, SR 37 and US 40. The mileage on those roads got weird, yes. But there were two others that were affected by the change…and one most people didn’t even realize.

SR 135 was rerouted from Troy Avenue to Thompson Road, cutting two miles out of the official route. This just required moving the little blue signs from north of Thompson Road, and surveying what else would need signs. And what wouldn’t.

The other route affect wasn’t even marked when it was decommissioned. Shadeland Avenue on the east side of Marion County was still legally SR 100 from I-465 to US 40 (Washington Street) until 1 July 1999. For the longest time, the only marker on SR 100 was a smaller blue sign below the reference post signs that read “100.”

INDOT has available on their website the RPS manuals for 2004, 2015 and 2016. Also available is the users guide from 1999. Here are the links for each: Users Guide200420152016

A Quick Look At Today’s State Roads, From A Historical View

A Facebook direct message from a reader of the blog started the research bug going again. Now, while I am still looking up information on his particular subject (transportation to Center Valley in Hendricks County, particularly a possible railroad there), part of his subject did come up. As well as a few others. Today, I want to look at the things that I have found while researching that topic…while not finding much about the topic.

The “town” of Center Valley is along the route that would become State Road 39 just north of the Morgan-Hendricks line. A post office existed there from 1855 to 1902. But what is important is the route that rumbles north to south through the town…the aforementioned SR 39. It wouldn’t be until 1932 when that section of SR 39 was added to the state highway system. But, the designation “state road” goes back quite a bit…like 1833.

The 17th General Assembly of Indiana passed into law several state roads. The first I want to mention would be the one that would make Center Valley (or, more to the point Centre Valley) a place. The route that would eventually become SR 39 was built as the Martinsville-Danville-Frankfort State Road. The southern end would be part of the state highway system from 1920 – the bridge over White River west of Martinsville. The northern end would be part of original State Road 6, connecting Lebanon to Frankfort. As original SR 6, it would become SR 39 with the Great Renumbering.

Two more state roads would from Martinsville would be added to Indiana with this meeting of the General Assembly. The first is one that would not become part of the state highway system. It was described as “an act to locate a state road from Martinsville, in the county of Morgan, by the way of Cox’s mill and Solomon Dunagan’s, in said Morgan county, to Stilesville, in the county of Hendricks.” This is an example of how the General Assembly would set up a “state road” through a particular person’s land. I would assume that what is now Tudor Road, southeast of Stilesville, was part of this road.

Another state road project including Martinsville did make it to the state highway system… eventually. The act created “a state road from Martinsville, in Morgan County, to intersect the state road leading from Madison to Indianapolis, at Edinburgh, in Johnson county by the way of Morgantown in said Morgan county.” This state road would be added back into the state highway system in the 1930’s…as State Road 252. A history of that road is available from ITH here.

But Martinsville wasn’t the only beneficiary of that particular meeting of the General Assembly.

A state road was created by the General Assembly to connect the town of Lagrange, in Tippecanoe County, to Logansport, in Cass County. Where is LaGrange? Well, it was a town along the Wabash River at the Warren-Tippecanoe County line. It was founded by Isaac Shelby in 1827…and had a post office from 1832 to 1835. It’s prime was with the Wabash Canal during the riverboat era. When the Wabash Railroad was built on the opposite side of the Wabash River, the town of LaGrange just dried up and disappeared.

Another road that was created at that time would connect Williamsport to the Illinois-Indiana State line via Lebanon (sic), now West Lebanon, and the now abandoned town of Chesapeake (about two miles east of Marshfield). This route will require some research.

Part of the road that would become, in time, SR 46 between Newbern and Bloomington would be added as a state road in 1833. The original road would start at the Michigan Road in Napoleon, travel through Camden (unknown today), Newbern, and Columbus to Bloomington. The section from Newbern to Columbus was part of the state highway system as SR 46, until INDOT truncated SR 9, turning the old SR 9 into SR 46.

Stilesville would be mentioned again as a state road was created to connect it to Crawfordsville via New Maysville.

The last road for this article would be a road that is still in existence, more or less, but not part of the modern state highway system. The description of the act was “to locate a state road from Green Castle, in Putnam county, to Carlisle, in Sullivan county, by way of Manhattan in Putnam county and Bowlingreen and New Brunswick, in Clay county.” Some day, I want to do more research on this road.

Lafayette Rail Relocation

Cover photo courtesy of Justin L. Grayson, as was the idea for the post.

When the railroads started coming to towns across the United States, it was a sign of prestige to have a railroad company build a line through the middle of a city street. While the towns thought it was something to be proud of, crossing the tracks was almost impossible. Lafayette was a town of rail crossings…and street running. As I have written about before, Lafayette was the home of several railroad lines. But toward the middle of the 1990’s, this was going to change…with the help of a lot of federal, state and local tax money.

1941 USGS Topo Map of downtown Lafayette, IN.

The actual beginning of discussions about relocating railroad tracks through the city of Lafayette occurred in 1926, when the city first proposed such relocations. Between 1963 and 1973, a series of engineering studies were commissioned by city officials to look at the possibility.

The idea of moving the railroad tracks through Lafayette started moving forward in 1974, when a study was conducted by the Stanford Research Institute (SRI). It was announced by Mayor James Riehle, on 11 July 1975, that a project director was named for the relocation. That director would be Herbert Thomas, vice-president of transportation at Kaiser Engineers, Inc. His local resident manager would be James Ellis.

It was also announced that day that the first two phases of the project would be completed in about ten months from that time. Phase one included the above mentioned SRI study. Phase two would consist primarily of engineering. The final two phases, design and construction, were not put on any schedule as of July 1975.

Mr. Thomas said “relocation plans here are not the biggest he has seen in the country, but said ‘the Lafayette project would be a major one for any city,'” as reported in the Lafayette Journal and Courier of 12 July 1975. He also referred to the “railroad-motor vehicle situation in Lafayette ‘a serious problem,’ noting that on a previous visit he was stopped by a train while hurrying to reach Weir Cook Airport.”

According to the Journal and Courier, “one important aspect of the Kaiser work will be to determine if the negative impact on the Monon Avenue area can be lessened.” Thomas said that “the alignment developed so far can only be reguarded (sic) as preliminary.”

One year later, in July 1976, Kaiser Engineering was set to begin look at the various alternatives to the new railroad location. Project Manager Ken Knevel said that the company would concentrate its work on the riverfront corridor since it received the most support locally. “Everything we’re doing now is just in response to individuals’ comments. The riverfront has been indicated as the preferred corridor.” (Source: Lafayette Journal and Courier, 24 July 1976.) Paul Stitt of the Norfolk & Western and Jack Smith of the Louisville & Nashville both agreed that the riverfront corridor would be best for both their companies’ operations. Conrail’s representative, John Partridge, said “otehr alternative corridors – bypassing the city and using the current N&W and L&N lines – is less satisfactory than the riverfront.”

The Louisville and Nashville, by way of their purchase of the Monon, was running trains through the middle of Fifth Street at the time. However, they did own a stub line that started just north of Main Street (and the Main Street bridge across the Tippecanoe River) traveling northeast to connect to the the street running route, and railroad yards, northeast of Fifth Street. Connecting this stub to the Nickel Plate and Wabash two blocks south along the riverfront would not be that much of a stretch.

Funding was going to be a constant problem, especially from the mid-1970’s to 1980. Washington had become very tight fisted when it came to money. The mayor of Lafayette had gone to Washington DC in March 1977 to ensure that funding would be available for the project through 1980. There were no guarantees.

There were as many as 19 railroad relocation projects in some sort of process in the late 1970’s. Lafayette had gained national attention because it involved consolidating three railroad companies into one line through the city.

Between 1976 and 1978, two neighborhoods were the focus of studies for the relocation plan. Those neighborhoods, the Wabash and the Monon, were going to be directly affected by the moving of the tracks.

The first construction phase finally started in October 1984, when Congress appropriated $7 million. Less than a year later, in September 1985, five homes were torn down to prepare to place Wabash Avenue 23 feet below the relocated train tracks. Things started looking bad again in 1987 when a pending Presidential Veto threatened $20 million in funding over five years for the project…and the insistence from Federal officials that state and local governments pony up 20% of the cost. Something in which INDOT said they weren’t really keen on participating. That veto was overridden by the House and Senate.

The next phase of construction after the override of that veto included a replacement for the Main Street bridge over the Wabash River, new approach ramps to the Harrison Bridge (now Old US 231) and a rail corridor between Ninth Street and Wabash Avenue to replace the Fifth Street street running tracks. A new $11 million North Ninth Street rail underpass was scheduled to being construction in late 1987.

Construction photo of the Lafayette Railroad Relocation, date unknown. Photo courtesy of Justin L. Grayson.

By 1994, the street running along Fifth Street had come to an end. According to the Journal and Courier of 22 July 1994, those were “crossings eliminated today.” Also according to the same newspaper graphic, phase 5 was to be completed in 1998-99 that would relocate the Norfolk Southern’s Wabash double-track corridor to the riverfront route, eliminating 24 crossings from Kossuth Street to Underwood Street.

Lafayette Courier & Journal, 2 August 2003,
announcing the end of the Railroad Relocation
Office in Lafayette.

The project’s offices would finally closed down on 1 August 2003. There were a lot of behind the scenes work that needed to be finished by the office, but the relocation was done. There was also one thing, historically, that was brought up when construction was occurring in 1993. While digging up the foundation of the old Big Four Station in Lafayette, some timbers from the Wabash & Erie Canal were found. The officials with the Railroad Relocation sent those timbers to Columbia, SC, for preservation. They were returned to Lafayette and given to the Tippecanoe County Historical Society for display.

The project would cost a grand total of $186 million in the end. It would not only affect rail transport through the area, but road transport changed as well. The old Main Street bridge in downtown Lafayette was changed to a pedestrian facility. Ultimately, all INDOT facilities in the city itself would be removed…leaving no state or US roads to downtown.

Indianapolis and the Original ISHC State Road System

I have posted much about the creation of the Indiana State Highway Commission. As of the posting of this article, the age of the Commission is either 103 or 101 years old. The original ISHC was established in 1917…but met with a lot of problems. It was finally nailed down in 1919 and made permanent.

This also creates a dating problem when it comes to the state highways. The first five state highways, then known as Main Market Roads, were established in 1917 with the original ISHC. Two of those original Main Market Highways connected to Indianapolis. The original National Road had been given the number Main Market Road 3. The Range Line Road, connecting Indianapolis to Peru, and through further connections, to South Bend, was given the Main Market Road 1 label.

When it was finally established, the ISHC changed the name of the Main Market Road to State Road, in keeping with other states surrounding Indiana. The markers used along the roads, painted onto utility poles like the old Auto Trail markers were, resembled the image to the left…the state shape with the words “STATE ROAD” and the route number. In this case, as of 1920, State Road 2 was the original route of the Lincoln Highway through northern Indiana.

The state highway system was designed to, eventually, connect every county seat and town of over 5,000 population, to each other. Indianapolis, as the state capital and the largest city in the state, would have connections aiming in every direction. Most of those roads marked with the original numbers would still be state roads into the 1970s and early 1980s, before the Indiana Department of Highways started removing state roads inside the Interstate 465 loop…and INDOT finishing the job on 1 July 1999. These road were removed for state statutory limitation reasons, and I have discussed that in a previous blog entry. So I won’t do it here.

The original state road numbers that came to Indiana varied greatly, as did their directions. There were no set rules when it came to state road numbers. They were assigned as they came…and stayed that way until the first renumbering of 1923, or the Great Renumbering of 1926.

Let’s look at the original state roads in Marion County, some of which actually did not reach Indianapolis itself.

State Road 1: As mentioned before, State Road 1 was originally called Main Market Highway 1. North of Indianapolis, it followed the Range Line Road, a local Auto Trail, through Carmel, Westfield, to Kokomo and points north. The route north followed Meridian Street north to Westfield Boulevard, then Westfield Boulevard on out to Carmel and beyond. In Carmel, the old road is still called Range Line Road, and serves as the main north-south drag through the town, as it does in Westfield.

South of Indianapolis, State Road 1, like its Main Market Highway predecessor, followed the old Madison State Road out of the city to Southport, Greenwood, Franklin and Columbus. The original SR 1 route is still able to be driven through the south side of Indianapolis, with the exception of the section replaced in the 1950s by the Madison Avenue Expressway. But Old Madison Avenue exists, if you can find your way back there.

While the entirety of original State Road 1 became US 31 with the Great Renumbering, bypasses in Marion County were put in place very early. The northern section, through Broad Ripple, and Carmel was replaced as early as 1930. The southern section, including the Southport/Greenwood bypass, was put in place in the 1940s.

State Road 3: As mentioned above, Main Market Highway/State Road 3 followed the National Road through Marion County. One exception to this is the section of the 1830s National Road that crossed the White River downtown. That section of the old road was removed in 1904 with the demolition of the National Road covered bridge and its replacement with a new, and short lived, Washington Street bridge. With a couple of exceptions other than that (the Bridgeport straightening of the early 1930s, and the new Eagle Creek bridge built in the late 1930s), the old road was followed very accurately until the mid-1980s with the creation of White River State Park. The successor to original SR 3, US 40, was moved to make room for the park. Both US 40 and US 31 lost their designations on 1 July 1999 with the removal of those two routes inside the I-465 loop.

State Road 6: This old state road was a through route when it came to Marion County. From the north, it followed the route of the original Indianapolis-Lafayette State Road from Lebanon. After passing through downtown Indianapolis, it left the county using the original Michigan Road on its way to Shelbyville and Greensburg. The original State Road 6 followed the Michigan Road Auto Trail, not the Historic Michigan Road, meaning it still went to Madison, but it went by way of Versailles, which the historic road did not. With the Great Renumbering, the northern SR 6 became US 52, while the southern SR 6 became SR 29 – later to be renumbered again to US 421.

State Road 22: This road, as it was originally laid out, only lasted from 1920 to 1923. Out of Indianapolis, it followed the old Mooresville State Road through southwestern Marion County. It was designated the original route from Indianapolis to Martinsville, as described in this blog entry. This road will be discussed again a few paragraphs from now.

State Road 39: Another 1830s state road that was taken into the Indiana State Highway Commission’s custody in 1919. This road followed the old Brookville State Road from the National Road out of the county through New Palestine to Rushville and Brookville. The original end of that road, both the 1830s original and the 1919 state highway, is discussed here. The road would become, in October 1926, the other section of US 52 through Indianapolis. It would also eventually become the first state highway removed inside the I-465 loop in Marion County. And even then, it would be rerouted in the late 1990s to go the other way around the county.

That covers the 1919 highways. More would come to Marion County before 1923.

State Road 12: Originally, this road, north of Martinsville, was the old State Road 22 mentioned above. When a new SR 22 was created, the SR 12 number was continued from Martinsville to Indianapolis along the old Vincennes and Mooresville State Roads. This road, in October 1926, would become part of the new State Road 67.

State Road 15: While the southern route of the Michigan Road was State Road 6, the northern part, heading off to Logansport, was added later and given the number State Road 15. The entire route of the historic Michigan Road would never become a state highway, but major sections did…although late in the creation of the state highway system. With the Great Renumbering, this road became SR 29, and in 1951, redesignated, like its southern half, US 421.

State Road 22: Here we go again. State Road 22 was given to the route between Indianapolis and Paoli. In 1919, that included the route along the west bank of the White River from Martinsville to Indianapolis along the Mooresville Road. This was changed by 1923 to keep SR 22 on the east side of White River, where it followed the old Paoli State Road, and the Bluff Road, through Waverly to the south edge of downtown Indianapolis at Meridian and South Streets. This was one of the routes of the Dixie Highway through Indianapolis, and would later become part of SR 37 in 1926.

State Road 31: In 1920, when this road was originally created, it turned south to connect to the National Road west of Plainfield. It had followed the Rockville Road from Montezuma to Danville, then turned southeasterly to meet State Road 3. By 1923, the road was moved from what would later become part of what is now SR 39 to continuing on the Rockville Road into Marion County. State Road 31 would meet the National Road outside the city limits of Indianapolis at what is now the intersection of Holt Road and Washington Street. It would become US 36 before it was extended along the new section of what is now Rockville Road to the intersection at Eagle Creek with Washington Street.

State Road 37: One of two state road numbers that still served Indianapolis after the road numbers were changed in October 1926 (the other being State Road 31). The original State Road 37 left Marion County in a northeasterly direction on its way to Pendleton, Anderson and Muncie. Inside the city limits, the street name was Massachusetts Avenue. When it reached the city limits, the name of the road changed to Pendleton Pike. This still occurs today, with the name change at the old city limits at 38th Street. In October 1926, the number of this road would change to State Road 67.

There were two other major state roads in Marion County, but they weren’t part of the state highway system until after the Great Renumbering. One was the Crawfordsville State Road, part of the original Dixie Highway, connecting Indianapolis to Crawfordsville via Speedway, Clermont, Brownsburg, and half a dozen other towns. It would be added to the state highway system by 1929 as State Road 34. The number would change later to US 136.

The other road was the original Fort Wayne State Road, also known as the Noblesville State Road, but even more commonly called the Allisonville Road. It would be added to the state highway system in 1932 as State Road 13. Less than a decade later, its number would be changed to the more familiar State Road 37.

State Roads, 1831 (Part 2)

This is a continuation of yesterday’s entry: State Roads, 1831 (Part 1). Remember: The concept of “state road” was completely different that it is today. Today, a state road is a road that has become the responsibility of the state transportation authority (for instance, now INDOT). Then a state road was a road that was authorized by the state, paid for by the state, but built and maintained by the county through which the road passed. So, basically, the state using Federal land proceeds to pay for, what will be, county roads. Some of these routes DID cross the line between the two different types of state roads.

Section 7: The section first listed in this act, from Frankford (Frankfort) to Delphi roughly follows US 421. The route to connect to the road that was mentioned in Section 6 of the same chapter, this road could have basically used a (more or less) straight line that follows SR 18 from downtown Delphi to SR 43. Or, followed what is now US 421 from Delphi to Michigan City. I am leaning toward the former.

Sections 8, 9 and 10: These sections talk about the Commissioners: their oaths, duties, paperwork to be done, and payment for service. Other things discussed was the fact that although the state is paying to make the road, it is the county’s responsibility to open and maintain them. The minimum requirement for the road to be open is that it be no more than 40 feet wide.

The three percent fund is the money that the Federal Government gave the state after the sales of Federal land. The state was given three percent of the sale price.

Section 11: Of the several places mentioned in this section, one (Baltimore) disappeared when the Wabash & Erie Canal was built on the opposite bank of the Wabash River, and another (Legrange) is very hard to find out any information. There is one old brick house left of Baltimore. It is located on SR 263 at Warren CR 1025S. (Strangely, Google Maps has SR 263 labeled “Old State Highway 63” as the street name.) The road starts at the Warren County line as Warren CR 600W. The original road has disappeared between US 136 and the old location of Baltimore.

Section 12: This is one of those “special acts” that I mentioned in my Indiana Toll Road(s) post on 24 May 2019. The state road starts at one person’s farm? Really? Exactly where IS Walker’s Farm in Parke County? At least from Clinton to Newport, the road roughly resembles SR 63 (or, at least, old SR 63).

The Acts of 1830, available here, shows more state road laws put into place that year. I will be covering those at a later date.

INDOT’s 12,000 mile limit

(Or: How do you get to Indianapolis?)

This entry originally appeared in the Indiana Transportation History Facebook group on 16 July 2014.

I have been asked many times why the state of Indiana has been removing roads from the state highway system. Other than the obvious reroutes for traffic efficiency, INDOT is limited by IC 8-23-4-2 as follows: “(a) The state highway system shall be designated by the department. The total extent of the state highway system may not exceed twelve thousand (12,000) miles.”

There is a lot more to the code (for instance: “The state highway system consists of the principal arterial highways in Indiana and includes the following: (1) A highway to the seat of government in each county.”

So why are there no state roads – other than I-65 and I-70 – in Indianapolis? The 12,000 mile rule appears here in glowing fashion.

I-465, for most of its length, is NOT just I-465. Other than the obvious I-74 multiplex (the official term for a road that travels the same path as another) on the west and south sides of the city, depending where you are on I-465, you could be on as many as SEVEN different routes. Take the two mile section from I-65 to US 31 South (East Street) on the south side. At that point, you are technically on I-465, I-74, US 31, US 36, US 40, SR 37, and SR 67. For maintenance recording, that is 14 miles of road in those two miles. For Indiana Code purposes, it is still only two miles. This allows INDOT to have more roads in the system while keeping to the 12,000 mile limit. (And for another fun fact, eventually that section of I-465 will also be part of I-69! That makes EIGHT routes that are in that very small section of interstate. And US 31, SR 37 and US 40 didn’t count until July 1, 1999. Prior to that, US 52 was on that section – but that was rerouted in the mid-90’s to the north side on 465.)

The beauty of bypasses is that they only count once, even though they may be numerous multiplexed roads.

The 12,000 mile limit also creates situations that simply do not exist in other states. For instance, when SR 44 was closed between Franklin and Shelbyville, the INDOT approved detour was north on I-65, to I-465, to I-74 to SR 44 east of Shelbyville. Other states have more state routes connecting places, and they tend to be closer together, making a 42 mile detour completely ridiculous. (The other INDOT route – consisting only of state highways – would have been only 32 miles via I-65, SR 252, SR 9 and SR 44. Still completely ridiculous, honestly.)