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Look at the landscape straight ahead. A small hill, not unlike the millions of other hills in Arkansas.
Apparently it was too big of a hill to go over.
They burrowed through. It’s .3 of a mile long and the only highway tunnel in Arkansas.
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Good observation Cheryl. It’s not a high hill. Why didn’t they go over it? Why didn’t they just dig part of it away to make it a bit smaller? Surely that would have been easier than building a tunnel under it.
Reasons for tunnels versus other: topographical, environmental, political, and other unknowns
Right Helianthus43!
I love the tunnel picture. It certainly gives the highway personality. I need to get my map out. Are all of these pictures on the way to Branson? I think Millard and I need to take a trip to Branson and see some shows. The traffic is so overwhelming though. We probably need to do that before school is out. And . . . . I hope we go down the same highway that these pictures are of. (grammar!!!!!)
This tunnel is just south of Fayetteville on I-540. So, no, not on the way to Branson (from here anyway.) 🙂
To All Here,
I know your posts here are very old, but I happen to run across them and wanted to respond to your questions of why this was not just run up over the hill instead of made into a tunnel. I am one of the engineers that designed this highway and tunnel and can answer that quite simply. The need for a tunnel here was very much a thing of technical and geological concerns. The strata of the soil, the pitch of the road when configured up and over the hill, even if the hill was gouged out a bit, would have been not conducive to supporting a stable and reliable roadbed and road surface. The roadway actually takes a dive when it gets about halfway through the tunnel so the tunnel is deeper under the hill than it looks when approaching from either direction. We made several different configurations of this stretch of road trying to omit using a tunnel and it just would not work. The strata of the soil was very tricky and would have been a giant headache to be able to make a stable roadway. Roads are designed to last 30 to 50 years and not putting a tunnel here would have made the roadway in this areas not last more than ten years. The landmass above the tunnel actually acts as a stabilizer for the roadway inside of it. If this road would have been run up and over the hill, a bridge would have been required for the roadway that is on top of the land that covers the tunnel. This, in turn, provided yet another obstacle to overcome when trying to get all of this to work together. The roadway above the tunnel was able to be left alone and it works quite well because they folks that live in this area that use the roadway above are able to keep on doing so without a lot of crazy up and down that a bridge would have caused. It is also much safer because bridges are always much more dangerous than a regular roadway. So, to sum all of this up, this configuration that was used with the tunnel is more cost-effective, more safe, and will make for a much longer-lasting roadway for all roads concerned in this area than with a conventional roadway just going up and over the hill with a bridge on top to accommodate the roadway that crosses over the tunnel. So that’s it in a nutshell.
Hey, Al, thanks for the backstory. Interesting. I’ll sure look at that tunnel differently now.
You are quite welcome. I am always happy to make things clear as to the reasoning behind design for any roadway, tunnel, bridge, dam, steel and concrete structures, drainage structures, and any other structures that I design. When there seems to be something strange or just doesn’t make sense in one of these structures there are always unseen factors that came into play during design and development of it. I actually am glad that I run across chat threads like this because it makes me and the other engineers know how people that come from miles away that see our designs for the first time and were not at city council meetings or question and answer sessions that happened during the concept, design and development of these structures. It also might make us aware of unforeseen problems with the design and lauout of the structure that could potentially cause safety concerns. This highway and tunnel won the excellence in concrete design, utilization and finishing award so we are very proud of it. But I think the most rewarding reason for liking running onto these threads is to see the comments of how much the users of these structures like them and enjoy using them. We design these things to make the world a bit more of a safe and enjoyable place than when we found it. We don’t like to displace a lot of vegetation or animal habitats, but sometimes it happens that we have to. But there are often new habitats that are created by our designs and also we try to keep the design to where it encroaches on those things as little as possible. I certainly love nature and the beauty of the wildlife and landscapes and these kinds of structures make for an environment where people can enjoy these things much more up close from our vehicles in a safer manner. This highway is among one of the statistically safer highways in the US and that is what we designed it for. As you may know, the old highway 71 route was terribly dangerous and claimed many lives each year. So this new highway was very critical to make the trip from Fayetteville to Ft. Smith much safer and it accomplished just that. Anyway, I did not mean to go on at length here. I just wanted to say a few things here to let you know even more of our thinking in the concept of this highway/tunnel system and to let you know how much I appreciate your posts here and being open and responsive to my explanations and comments. Have a great week and keep on enjoying the roads and highways here in Arkansas. : )