AARoads Forum

Regional Boards => Southeast => Topic started by: Team445 on May 14, 2020, 04:22:36 PM

Title: I-840 I-24 interchange design
Post by: Team445 on May 14, 2020, 04:22:36 PM
Does anyone else agree this cloverstack interchange is poorly designed? There is only 576 feet between the two cloverleaf ramp gores on I-840 eastbound.
Title: Re: I-840 I-24 interchange design
Post by: mvak36 on May 14, 2020, 06:17:33 PM
^It doesn't look too bad. I think most I've seen are about the same.
Title: Re: I-840 I-24 interchange design
Post by: triplemultiplex on May 15, 2020, 12:37:39 PM
I've always found the placement of the NB->WB loop ramp to be rather unique.
It's almost as if when they built the I-24 to I-40 section, they built the interchange anticipating the full build-out would include a NB->WB turbine ramp. But then when the time came to build the other half of the interchange, decided that was too pricey and had to work around the existing SB->SB turbine.

That's probably not the case, considering how interchanges at both ends of I-40 were designed with earthwork and ramp stubs for the final build-out that will never be.  Seems logical that the 24/840 design was going to be that way from the get go.
Looking at an aerial from 1997 when 840 was still under construction west of I-24 and a lot of the earthwork for incomplete half of the interchange looks like it was already in place.  I see no break in the landscaping between the future ramps and the open ramps, so that leads me to assume it was constructed all at once, possibly even including the as-yet unused bridges over I-24.

I'm sure there's some folks around here who would remember.
Title: Re: I-840 I-24 interchange design
Post by: wriddle082 on May 17, 2020, 08:57:28 AM
I've always found the placement of the NB->WB loop ramp to be rather unique.
It's almost as if when they built the I-24 to I-40 section, they built the interchange anticipating the full build-out would include a NB->WB turbine ramp. But then when the time came to build the other half of the interchange, decided that was too pricey and had to work around the existing SB->SB turbine.

That's probably not the case, considering how interchanges at both ends of I-40 were designed with earthwork and ramp stubs for the final build-out that will never be.  Seems logical that the 24/840 design was going to be that way from the get go.
Looking at an aerial from 1997 when 840 was still under construction west of I-24 and a lot of the earthwork for incomplete half of the interchange looks like it was already in place.  I see no break in the landscaping between the future ramps and the open ramps, so that leads me to assume it was constructed all at once, possibly even including the as-yet unused bridges over I-24.

I'm sure there's some folks around here who would remember.

You are correct.  The entire 840/24 interchange was built out all at once in the mid-90ís, including new Florence Rd bridges over both highways.

TDOT really underestimated how much traffic would utilize the loop ramp from EB 24 to NEB 840 since itís a good shortcut to the north side of Murfreesboro (TNís 6th largest city that now has over 100k population).  They built out most of the major interchanges to try to give the highest speed connections to ramps exiting 840 heading away from Nashville, and ramps on 40/65/24 from Nashville-bound directions heading towards either direction of 840.  The other ramps seem to have been afterthoughts.