FRED FLETCHER-FIERRO HOST : It’s Morning Edition; I’m Fred Fletcher-Fierro. Tomorrow is a big day if you drive Highway 171 north of Carl Junction, Missouri. At around 10 AM Tuesday the Missouri Department of Transportation will close 171, at Routes 96 and YY so they can complete a nearly 10 million dollar roundabout project that will keep that intersection closed for up to 60 days. Recently, I spoke with James Howell with MODOT, who says the construction of the project is the tip of the iceberg.

FRED : Howell says, along with the roundabout construction MODOT is adding some improvements to Highway 171 as it passes through Carl Junction. He also says to keep in mind that the highway will remain open south of the construction area. And to look for detour signage that will guide drivers around the construction site.

JAMES HOWELL : Typically, a project like this is going to take several years in the making. It’s going to get put on our STIP, our Statewide Transportation Improvement Plan. It’s going to go throughout entire design process and that’s going to entail your vetting of your crash history, your alignment segments, any right of way purchases, utility relocation, things of that nature, before it gets into the construction phase which we are in now.

FRED : According to James Howell, with MODOT, the intersection at Highway 171 and Routes 96 and YY handles about 9,000 cars and trucks on average per day. He says that before settling on a roundabout MODOT looked at constructing a bridge that would go over to the railroad tracks at the intersection. Howell estimated the cost of an overpass as much as 30 million dollars, three times the cost of this project. Howell says the primary focus of the roundabout at this intersection is to alleviate traffic jams at the train tracks.

JAMES : One of the main concerns, obviously, is the rail road tracks that run adjacent to 171 there, at 96 and we also have a YY intersection that crosses the railroad tracks that tie into 171. We have had some accidents at this location in the past, due to that grade change, that elevation. So the roundabout is getting implemented to address some of those grade changes. And also from a safety standpoint try to eliminate a lot of those t-bone type collisions that we’ve seen at this location in the past.”

FRED : Once completed Howell says that drivers will notice the roundabout and roads leading in and out of it will be set off to the east to allow more room for big rigs to navigate the train tracks. MODOT is also raising the grade elevation to lessen the percent slope coming off of the tracks to reduce the amount of high centering that can occur with large trucks going over the tracks. He says that designers looked into other options to better navigate traffic at the intersection, but that a roundabout was the best choice.

JAMES : As far as anything we could have done, you a signal at this intersection, really the way our signals work would not have been a good fit in this area with the train tracks in such close proximity. There would have been no way for the system itself to work in that capacity. The other alternative was a divided road crossing, basically an overpass at that location. But due to some ramp configurations, just the general cost of that type of an interchange at that location with the ADT’s that we’re seeing, it was just not warranted. So MODOT’s design team really felt like this was the best fit for this situation.

JAMES : Along with this project, we’re going to overlay and work on some of the shoulders, on Route 171 as well as adding turn lanes, at Young Road, and also extending the turn lanes at Fir Road there in the Harp’s gas station area. So you’ll also be seeing those two activities go on as well. Now, as far as the closing limits, we’re only going to be closing through the YY and 96 interchange limit there for a half mile on either side of that. Traffic will be advised to use the detour routes.

Those detour routes are going to be H and M. Traffic should use eastbound, M highway down to 43, if they’re coming to Pittsburg from Joplin. And then, if they’re going back to Joplin, backup from Pittsburg area, they’ll want to use, Route 43 up to H, to head into that westbound, northbound direction. And then if you’re coming off of YY for any reason we ask that you use Route Z through Carl Junction there to get back over to 171.

FRED : James Howell, with MODOT speaking about the closure of Highway 171 and Routes YY and 96. The closure takes place tomorrow at about 10 AM. The intersection will be closed for up to 60 days.