Roundabouts, DDIs & other Intersections

Springfield Public Works constantly works to improve traffic flow and safety. New intersection safety measures may not always be popular with drivers initially, but can have a big impact on everybody's safety.  

  1. Diverging Diamond Interchange
  2. Roundabouts & Traffic Circles

Diverging Diamond Interchanges

The City of Springfield, Missouri was the first in the northern hemisphere to build this type of intersection. Today, MoDOT  has built five DDIs on Springfield's State Routes and they have proven themselves to be very effective in relieving congestion and eliminating severe crashes. A 2-year before-after study of Springfield DDI locations has shown that the typically severe angle crashes have been reduced by 90% percent. As expected with a curvy roadway, lane-change and lane departure crashes have increased. However, overall crashes have gone down by about 30% and injury crashes have dropped by almost 60%. 

Further, Diverging Diamond Interchanges can move traffic much more efficiently than a conventional interchange: While it used to take 8 different signal phases to give each approach their turn, now there are only two signal phases needed to serve all directions.

Tips for driving in Diverging Diamond Interchanges:

  • Know where you are going. Get in the correct lane before you enter the DDI.
  • While a right turn from the off ramps is permitted after a stop, only turn if you feel comfortable with this type of intersection and you know where traffic is coming from. If  you cannot safely turn, wait for the signal.
  • You are not allowed to do left turns on red.
  • Slow  down and be alert.