NOT as the Crow Flies

All due credit for the article today goes to a reader using the pseudonym "Wangi." He sent me an email message offline noting an interesting situation, which by implication suggested the basis for another contest. I even stole the title of the current article from him. Thank you, Wangi!

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There’s nothing unusual going on here, right? This is a one mile (1.6 kilometre) stretch of motorway outside of Edinburgh, Scotland. Open that map in another tab though, reverse the directions (the little button with the up and down arrows next to the origin and destination information) and notice the result. A simple 1.0 mile trip from Point A to Point B becomes a 16.3 miles (26.2 km) odyssey when returning from Point B back to Point A. The lesson to be learned with this simple exercise: a motorist taking the wrong exit near Edinburgh will have a bad day.

Wangi wanted to know, "what’s the longest round trip for what should be a straightforward 1 mile?" I’ll take my shot at a roundabout answer and then turn the same question over to the 12MC audience playing at home. The key, I think, is embedded within the design of limited access highways. Find a roadway with the longest distance between exits and one stands a pretty good chance of solving the puzzle. There might be other situations causing lengthy reverse trips and I’ll get to some of those momentarily. I’ll concentrate on limited access highways first.

U.S. Interstate Highways

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I’ll stick with what I know and examine the Interstate highway system in the United States. That leaves the rest of the planet to 12MC readers worldwide to scour for better examples. I had a hazy recollection of the longest distance between exits somewhere in western Utah, an interesting situation brought to my attention by a reader after my drive through the Bonneville Salt Flats a couple of years ago. I also noted that I’d experienced a similar situation when I drove across the Lake Pontchartrain Causeway in Louisiana. Get on either of those roadways and it’s going to be a long time before one will be able to loop back to the start.

Notice the Bonneville example, above. This solution leverages a 37 mile (59.4 km) gap on Interstate 80 between Exit 41 at Knolls and Exit 4 at Bonneville Speedway. It’s one mile heading east-to-west and then 74.1 miles (119 km) to return to the original starting point. A fictional trip taking 48 seconds in one direction will take about 1 hour and 4 minutes when reversing Google Maps’ directions.

A one-mile Lake Pontchartrain Causeway trip, by the way, would take 47.9 miles (77.1 km) when reversed. That’s a healthy distance (map) although it falls well short of Bonneville. It’s also not an Interstate highway segment, which leads to the next slice to be considered.

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U.S. Limited Access (Non-Interstate) Highways

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Florida’s Turnpike includes an insanely long segment without exits between St. Cloud and Yeehaw Junction, formerly known as Jackass Junction. The 48.9 mile gap is reputed to be the longest in the United States of any road. Miss that exit and one will feel like a Jackass because reversing a one mile trip will take 104 miles (167 km) as Google Maps displays it.

In reality, the Canoe Creek Service Plaza (map) sits between the lanes and caters to traffic heading in either direction. One could flip sides there safely. No physical barrier seems to prevent it. It’s still going to be a humongous detour, just not as bad as it may appear at first glance. Nonetheless, Google Maps does not recognize it as an option which leads me to wonder if it’s legal. Toll roads sometimes have odd rules. Does anyone have first-hand experience with Florida’s Turnpike and know the answer?

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Other Possibilities Worth Exploring

My stop at the Alpine Visitor Center several years ago

What’s the longest reverse direction that doesn’t involve a limited access highway? I’ve already mentioned an example that involved a bridge, and there may be longer ones. Another possibility might be one-way scenic loops. There are several in the National Park system. I’m personally familiar with Old Fall River Road in Rocky Mountain National Park (my visit). It’s limited to uphill traffic because it’s narrow, gravel and full of switchbacks. Eventually it arrives at the Alpine Visitor Center at an elevation of 11,796 feet (3,594 metres) and connects there with the Trail Ridge Road. Google seems to think Old Fall River Road allows two-way traffic (map) — it does not — so I can’t calculate the the exact reverse distance easily. I’d estimate it to be about 25 miles give-or-take.

I’d be curious to find the most extreme distance reversal differences in a urban setting. The one-way roads that users offered in Just Keep Turning offered some interesting possibilities. Reader "Pfly" highlighted a good example in Rome with a fairly significant percentage difference when reversed (map).

I think this should be examined in categories: biggest differences for limited access motorways; for bridges; for loop roads; for urban environments and whatever else seems meaningful. It’s not fair to compare Florida’s Turnpike to Rome.

Lake Pontchartrain Circuit

We continue to tour along the Gulf, including a couple of day trips into Louisiana from our base on the Mississippi Coast. I’ve developed from those odysseys what I think is a great itinerary for any beer-loving aficionados of geographic oddities who need to entertain the kids. I’ll admit that it’s a very small demographic so perhaps only the readers of the Twelve Mile Circle will be able to appreciate this in its proper context. Anyone choosing to replicate the circuit can, of course, add or subtract destinations to suit one’s tastes.

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The day starts at the Global Wildlife Center near Folsom, Louisiana. Drill in on the map and you’ll notice that the closest named-place is actually "Cranky Corner" which amuses me to no end, but I suppose that wouldn’t look so good in their promotional material.

They loaded everyone onto modified wagons pulled by a tractor for an hour-and-a-half ride through a Louisiana version of the African plains, while herds of animals followed along in hopes of handouts and a quick meal. The kids loved it, and I have to admit that I enjoyed it as well.

From here it’s an easy jaunt to Abita Springs, home of the Abita Brewery. With proper timing, one can eat lunch at their brewpub in the quaint downtown area of Abita Springs, and then head over to the actual brewery a mile further along the road for a 2:00 tour.

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I’ve been wanting to drive across the Lake Pontchartrain Causeway, supposedly the world’s longest continuous bridge over water, for ages. In fact I whined about it during my last visit to the area a couple of years ago. This time I drove it, all 24 miles (38 kilometres) straight across the lake from Mandeville on the north shore to Metarie on the outskirts of New Orleans. It’s surprisingly less boring than one would imagine. Sure, it’s incredibly straight, but there are a number of elevation changes that allow ships to pass beneath it. Those add some some hilly variety to the drive.

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New Orleans is defined by the Mississippi River. I’ve been here many time so I didn’t stop to tour around the city. Certainly most "normal" tourists would want to include some time here during this itinerary. No, I had more important things to do. I wanted to take a ride on the Belle Chasse ferry.

The two portions of Plaquemines Parish split by the Mississippi River have no natural land route between them. The nearest bridge is all the way up in New Orleans, and that can become horribly inconvenient given the traffic of the city. The natural solution is a short ride across on a ferry lasting all of about five minutes. Loading and unloading actually took much longer than the ride itself. This was also my first visit to Plaquemines Parish so score one more on my County Counting list.

I’ll focus on some of the sites in Mississippi in my next post.

Lake Pontchartrain Bridges

I marveled at the sheer size of Lake Pontchartrain as I traveled between my brief stops in New Orleans, Louisiana and the Mississippi Gulf Coast, crossing several miles of open water as it rolled beneath Interstate 10 in a stiff breeze. The Twin Span Bridge still showed signs of extensive damage from Hurricane Katrina. Dark, rubbery, temporary sections filled long gaps in the concrete that washed away during the storm more than two years ago. Cranes on barges lifted construction material into place a few hundred yards to the east for a higher, wider replacement bridge that was well underway.

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While the Twin Span Bridge is impressive, there is a much more remarkable structure crossing the lake. The Lake Pontchartrain Causeway cuts straight across open water for 24 miles (38 kilometers). It is the longest bridge on earth, and stretches from the New Orleans suburb of Metairie to the north shore town of Mandeville.

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This satellite photo shows both the Twin Span Bridge (right) and the Causeway Bridge (center). The Twin Span Bridge, which is actually rather impressive in length, looks positively puny in comparison. Unfortunately, as much as I wanted to, I didn’t get a chance to drive across the Causeway Bridge on this particular trip. When I noted that during our journey I got an odd look in return from the family since they’ve grown accustomed to being dragged to what they consider unremarkable spots. It’s true, I’ve driven much further for sights even more obscure.

If only I’d had just one more day.