I used to drive between Washington, DC and Chapel Hill, North Carolina, nearly every weekend for about eighteen months a number of years ago. I became very familiar with the route and every landmark placed upon it, as one might imagine. One of those included an exit for Boydton Plank Road along Interstate 85 near Petersburg, Virginia. I thought it had to be hyperbole. A plank road? Really? An actual wooden road constructed of boards, I’d smirk sarcastically. Much later I learned that plank roads actually did exist for a period of time, including this one.
Boydton Plank Road
Lots of great resources on this topic exist on the Intertubes. The U.S. Federal Highway Administration’s "Back in Time – Plank Roads" and the Michigan Department of Natural Resources’ "The Plank Road Craze" both provided excellent overviews. From the FHWA:
A modern movement at that time [ed., late 1840’s-1850’s] called for the building of wooden roads, a great improvement in transportation… wagons loaded with merchandise and agricultural products — and the animals pulling them — were not slowed or stopped by mud, but could enjoy a hazard free ride once they reached a plank road… Plank roads were still popular into the 20th century where the first motorists, struggling to negotiate muddy roads and bumpy gravel roads with their Model T, were all too happy to have a level surface on which to drive.
Plank roads were expensive and they required vasts amount of lumber. U.S. states, and especially those on the frontier, often did not have sufficient resources to build and maintain them. They allowed private companies to construct plank roads speculatively as turnpikes, with tolls used to cover ongoing repairs and hopefully provide a financial return for investors. The Michigan website mentioned "A total of 202 plank road companies" receiving charters from the state in the last half of the nineteenth century, with the preponderance of them bestowed right around 1850 plus or minus a couple of years. Other states did the same. One of the longest was built in North Carolina, the 129 mile (208 kilometre) Fayetteville and Western Plank Road constructed between 1850-1852. That was the heyday of the "plank road craze."
There were a couple of issues leading to the demise of this unusual road-building technique. First, wood exposed to the elements didn’t last very long. Maintenance costs began to soar after only three or four years. Second, railroads became increasingly popular, expanding their networks exponentially as the century progressed. Plank roads got a bit of a reprieve in the early days of the automobile and then quickly disappeared under ribbons of asphalt.
I never did stop at Boydton Plank Road even though I drove past it dozens of time. That was a pity since it was also an historical site. It saw combat during the Civil War, the Battle of Boydton Plank Road, October 27-28, 1864. Of course, it’s difficult to go anywhere in Virginia without running directly into a Civil War battlefield before long.
Did any of those old plank roads still exist, I wondered? In a sense they did. There must be hundreds upon hundreds of streets with Plank Road somewhere in their names. I’ll bet there’s one near the hometown of every 12MC reader in the United States or Canada. The closest one to my home might be about an hour away in Fredericksburg, VA. Their names carried forward to the present day although their roadbeds were long since paved.
Glamis-Thanksgiving 2008 by Sandy & Co., on Flickr
via Creative Commons Attribution-NonCommercial 2.0 Generic (CC BY-NC 2.0) license
West of Yuma on the California side of the line, down along the Mexican border, deep in the desert, exists what may be the only remaining original section of an historic plank road.
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It survived because it was built during the very latter-part of the plank road era, 1915, and because it was set in an extraordinarily dry area where it didn’t rot. The Bureau of Land Management protects the remaining segment, a mere 1,500 feet (457 metres).
This wooden road once spanned the Imperial Sand Dunes, providing a means of commerce and transportation to the southern Imperial Valley… Before the construction of the plank road cars were forced to go around the dunes, either south through Mexico, or the more popular northern route, through Brawley. The Brawley route presented its own challenges, going directly through Mammoth Wash, which was known for its flash floods that could sweep cars away in a matter of minutes.
Today, Interstate 8 follows much of the original plank road path through the dunes.
Old Plank Road Trail by reallyboring, on Flickr
via Creative Commons Attribution-NonCommercial-ShareAlike 2.0 Generic (CC BY-NC-SA 2.0) license
Another plank road survived in spirit in Illinois in the guise of the Old Plank Road Trail (which also served as a railroad route after the demise of the plank road itself). It runs from Joliet to
Forest Park Park Forest and receives 128,000 recreational users per year (route).
Illinois was also the home of an original plank road toll house, preserved at the Dickson Mounds Museum: "This structure is one of perhaps only a dozen plank road toll booths still surviving in the United States. It is one of two known wooden structures and the only one with an onion-shaped dome" (map).
Last place went to the Plank Road Brewery, the makers of Icehouse Beer. The Brewers Association, a trade group for small and independent brewers, would describe Plank Road as a "Crafty" brewery rather than a Craft brewery. The name attempts to pass itself off as a small brewer when really Plank Road is a subsidiary of Miller Brewing, which in turn is a subsidiary of SABMiller. The Plank Road in the title referred to the street that passed by the old Miller Brewery during the plank road craze, the Watertown Plank Road.
I stumble across the most fascinating bits of information in unexpected places. It happened this time as I examined the unusually-wide median strip between the eastbound and westbound lanes of Interstate 8 in southern California. I learned of a nearby oddity further down the highway while reviewing various roadfan websites.
A motorist will encounter the lowest overland elevation in the entire Interstate Highway System just to the east of the extreme central reservation I’d discovered earlier. It is listed as 52 feet (16 meters) below sea level by the U.S. Government’s Federal Highway Administration.
It’s not the lowest elevation of any road of any type within the U.S. — that’s Badwater Road in Death Valley which provides access to the lowest public restroom in North America (~ -282 ft, -86 m) — just the lowest natural point of elevation in the Interstate Highway System. It’s still pretty impressive, though.
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This happens in the vicinity of Exit 107 where I-8 crosses the New River. Notice the channel. The road dips down here as it crosses the river over a short bridge. Where, I wondered, could the New River be flowing if it was already more than fifty feet below sea level here? Certainly it would not be flowing to the sea. It much be part of an endorheic basin, and indeed that is the case.
The New River begins in Baja California, Mexico where it’s known as the Río Nuevo. It passes through the wonderfully conjoined portmanteau cities of Mexicali and Calexico. From there it flows under the I-8 bridge west of El Centro, and on to the Salton Sea. The surface elevation of the Salton Sea is -226 ft (-69 m) so whatever flows along the New River won’t leave the Salton Sea on its own unless it’s able to evaporate.
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That’s a problem. This Street View image from the point of lowest Interstate elevation shows one of the most polluted bodies of water in the nation. Sewage, pesticide-laden agricultural runoff, and industrial waste from businesses located along the ditch then dump into a basin without an outflow. Toxins and pathogens collect in extreme concentrations, creating a most foul situation. Those driving at high speed along I-8, crossing this point of lowest elevation, likely never consider the drawbacks of this dubious honor.
Let’s put one more asterisk onto the claim. There are other places along the Interstate Highway Systems with a lower elevation. However, they are located in tunnels. A similar situation exists in Canada.
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The Intertubes claims that the Fort McHenry Tunnel carrying I-95 traffic through Baltimore, Maryland represents the absolutely lowest Interstate elevation at 107 ft (33 m) below sea level. It passes in close proximity to historic Fort McHenry, as implied by the name, the battlefield site inspiring the Star Spangled Banner. It then drops below Baltimore Harbor. I’d post a Street View image except that the interior of a tunnel isn’t exactly the most exciting scenery available (check for yourself if you must).
While the exalted position of the Fort McHenry tunnel seemed to be conventional wisdom for the cyberspace masses, it was not the only candidate offered. I discovered numerous other claims. I could not, however, nail-down a definitive source. Another option included the I-93 Thomas P. "Tip" O’Neill Tunnel, part of the Big Dig project in Boston, Massachusetts. The I-64 Hampton Roads Bridge-Tunnel in Virginia was also mentioned frequently. I know we have several roadfans who read 12MC regularly so hopefully someone can provide a proper citation and we can put these issues to rest. I’ve driven through all three of these tunnels so I’m covered no matter how it turns out. Funny, I never realized I was experiencing a true geo-oddity during any of my transits.
I’ve never driven on I-8 through California though. I look forward to experiencing both the wide median and the lowest overland elevation someday.
It started out as it often does through a chance encounter with a roadmap anomaly. I happened to be examining a stretch of highway online. Then I spied an uncharacteristically wide split between the westbound and eastbound lanes of Interstate 84 directly outside of Pendleton, Oregon.
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It seemed quite remarkable. A mountain ridge forced opposing lanes to split and separate by an unusual distance. I used mapping tools to measure a line directly across the opening to estimate the greatest separation, which I calculated at around 1.7 miles (2.7 kilometers). This required a level of subjectivity. I attempted to measure between equivalent points on opposing lanes, measured almost horizontally in this instance. Obviously longer distances could be calculated by angling the line. That felt like cheating though. I decided to stick with my original estimate, giving or taking a small amount to account for eyeball-level accuracy, and wondered whether I could discover roads with greater separations.
Likely candidates went by different names such as
duel carriageway, freeway, motorway or divided highway, based upon linguistic variations of English-speaking nations. Likewise the separation between opposing lanes might be called a central reservation in the United Kingdom or a median strip in the United States, as examples. These terms could be mixed-and-matched to target online searches for better candidates.
Let’s dispel with the knee-jerk candidate right away.
Exibir mapa ampliado
An Intertubes mythology has coalesced around Brasília’s Monumental Axis ("Eixo Monumental"). This impressive roadway defined a core for Brazil’s capital city, a feat certainly worthy of recognition. This also created an uncorroborated notion that Monumental Axis was either the widest road or the widest central reservation on the planet. Clearly it is neither. I measured the median at 0.25 miles (0.4 km). That’s a wide spot for Brazil perhaps although completely unremarkable when compared to the Pendleton split.
I wasn’t the first to ponder this question. Others blazed a trail before me and recorded numerous instances, including the Pendleton example I felt so smug about "discovering" a few days ago. A roadfan discussion and an FAQ proved to be particularly helpful so I stole from those sources liberally. Examples going forward should be ascribed to people who mentioned them there. I was too lazy to find any other instances on my own.
My crude measurements suggested co-champions, one in Canada and one in México.
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The Trans-Canada Highway presented a paradox, a 2.6 mile (4.2 km) separation for no apparent geographic reason, located outside of Ernfold, Saskatchewan. There weren’t any mountains to bypass. Muskeg wouldn’t be an issue this far south. I did notice a number of small lakes and ponds within the vicinity although those should have been negotiated with ease by highway construction crews.
I may have found the answer. The original highway, now the westbound lanes, swung to the north and passed through Ernfold. The eastbound lanes came later. Those lanes took a more direct path, avoiding further traffic through a residential area while reducing construction costs.
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Down along the border between México and the United States, a common geographic formation created dueling companion instances with the more impressive one located in México.
I measured the Interstate 8 median strip east of San Diego, California at 1.5 miles (2.4 km). The distance between opposing lanes of Mexican Federal Highway 2D as it stretched from Tijuana to Mexicali came in at around 2.6 miles (4.2 km). That was the same as the Canadian example, once again within the margin of error of eyeball precision. I am sure one or the other occurrence could claim the crown with improved criteria and measurement.
One other United States location often surfaced in discussions, a stretch of Interstate 24 outside of Monteagle, Tennessee (map). I measured the width of the median at 1.7 miles (2.7 km), the same as Pendleton, so I’d call these a tie for the greatest US distance unless someone finds a better location.
Sometimes examples from the United Kingdom surfaced. They did not compare favorably.
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The M6 at Shap near Junction 39 received frequent attention. One source noted that " Junction 39 is the highest junction on the M6 being less than half a mile from Shap summit, the highest point on the M6." That would seem promising. I measured it at 0.2 miles (0.32 km) which was even as much as Brazil’s Monumental Axis. Others suggested the A611 at Annesley (map). The central reservation appeared to have a similar width. They were both noteworthy for the UK although neither contended for the world title.
Canadian and Mexican examples, both with 2.6 mile (4.2 km) median strips, were the best that I could find during my cursory search. Certainly we can do better.