Extreme Reservations

On January 8, 2013 · 8 Comments

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.

View Larger Map

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 dual 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.

View Larger Map

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.

View Larger Map

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.

View Larger Map

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.

On January 8, 2013 · 8 Comments

8 Responses to “Extreme Reservations”

  1. Macedonian says:

    Check out split between M1 traffic lanes in Macedonia: SOuthbound lanes are along Vardar river, and northbound lines are behind the mountain…


  2. Marc says:

    Loved this post. Saw the image and knew exactly what you were about to discuss. That stretch of I-84 is called Emigrant Hill but is more commonly referred to as Cabbage Hill. In addition to being thought of by nerds like me as the widest gap in the US interstate system, it is also one of the most dangerous stretches of interstate. I drive that stretch 3 or 4 times a year (usually in winter…eek) and in my experience it generally has one of three conditions: Dense fog, snow cover, or clear skies (and an amazing view of Pendleton) but extremely windy. When we drive through there we always consider it a relief to make it to the other side in one piece. Here in Portland, we hear about fatal crashes on the hill several times a year.

    Here’s ODOT’s trucker warning: http://www.oregon.gov/ODOT/MCT/docs/emigranthill.pdf

  3. Joe says:

    I-24 in Tennessee can give I-84 a run for its money for the widest split in the US. Depending on how you calculate and what you consider to be perpendicular to the highway, you can get anywhere from 1.6-1.8 miles between I-24 as it makes its down down the Appalachian Mountains.


  4. Paul Hardy says:

    The British term is “Dual Carriageway”, not “duel carriageway” – that is dual as in “consisting of two parts”, not duel as in “a contest with deadly weapons”, although given the rate of carnage on the world’s roads, that may be a Freudian slip (“an unintentional error regarded as revealing subconscious feelings”)!

  5. Aaron of Minneapolis says:

    This stretch of I-90 above Dakota, Minnesota, isn’t exactly world-record-setting (about 1500 ft/500 m by my eyeball estimate on Google Maps), but it’s probably the widest in the state, and it was definitely the widest I could think of offhand. 🙂 The two sides run on opposite sides of a valley in a very hilly area near the Mississippi River. There are even houses and farm fields in that part of the median.

Comments are closed.

12 Mile Circle:
An Appreciation of Unusual Places
Don't miss an article -
Subscribe to the feed!

RSS G+ Twitter
RSS Twelve Mile Circle Google Plus Twitter
Monthly Archives
Days with Posts
December 2017
« Nov