Roadscapes Stuff

Roadscapes Wednesday: Why A Roundabout Was Chosen For Bynum Leatherwood Road


It’s in the news, and people are leaving comments on social media disapproving of this idea.  But you might as well get used to it.  Coming soon, a roundabout is coming to the intersection of Bynum Leatherwood Road and Old Gadsden Highway.

The current setup is a simple traffic light intersection.  The problem with the current setup is there are no turn lanes.  And there are major traffic backups at this intersection as traffic mostly from the Anniston Army Depot waits to either turn left onto Old Gadsden Highway or turn right onto Bynum Leatherwood Road.

I spoke to people at the Calhoun County Highway Department, and they showed me two potential plans to upgrade this intersection.  One was to keep the traffic light and add turn lanes, the second was to redo this intersection and create a roundabout.

The highway department had a traffic study conducted, and below you can look at the numbers.

You can see the AM peaks and the PM peaks has a ton of traffic.  You can see the capacity analysis approves greatly with either plan.  Cutting it down from over 170 to 49 is a major difference.  As for the heaviest choke points, a traffic light with turn lanes would be the better option for the PM peak.  But, the roundabout is the better option for the AM peak.  Outside the heavy traffic peaks, the roundabout often beats the turn lanes.

So why is Calhoun County going with the roundabout?  It’s not only because the traffic study suggested it was the best option.  It also has to do with cost.  If you look at this intersection, you notice a creek running under the road in several spots.  To do the traffic light with turn lanes, the county would have to expand the culverts and buy more land for right-of-way.

The county wants to approve the intersection for the lowest cost possible.  It is also encouraged to use roundabouts as ALDOT is wanting more of them.  And let’s face it, the roundabout is the safest form of intersection there is.  A traffic light with turn lanes would have 12 points of contact (straight, left, right).  While a roundabout would have only four points of contact.

Most of the world uses roundabouts in many places, and I believe it’s time the United States sees more of them.  No, it’s not an invasion, and you will get used to the roundabouts.  This project is to improve a dangerous intersection for the lowest cost possible to taxpayers.  A roundabout would only be around $800,000.  And traffic light with turn lanes would easily double that cost.

Below is what this roundabout will look like once constructed.  Construction should be wrapped up in 2020.

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