http://www.joplinglobe.com/local/x685074247/Work-begins-Monday-on-I-44-and-Range-Line-interchange
I-44 at Range Line Rd (Bus US 71) is being turned into a Diverging Diamond Interchange. This will be the second DDI along I-44 and the seventh in Missouri over all.
I've noticed that Missouri is pretty gung-ho on DDIs. It's made me wonder if it will eventually regret it later. How much increase in traffic can a DDI stand before it too becomes overloaded?
Quote from: kphoger on August 13, 2012, 02:21:18 PM
I've noticed that Missouri is pretty gung-ho on DDIs. It's made me wonder if it will eventually regret it later. How much increase in traffic can a DDI stand before it too becomes overloaded?
Well, I think the only thing that would overload a DDI is if there are ramp meters on the onramps. Which I would have to think would limit its usage in certain metro areas (Denver and MSP, I'm looking at the two of you).
^ IIRC there's a point where if through traffic volumes get too high DDI's start breaking down and can have issues with backing into adjacent intersections. This can be compensated for with additional lanes through the DDI, but this can get problematic with adding/droping the additional lanes outside the DDI.