I-90 - SR 18 - Interchange Improvements - Diverging diamond interchange

A Diverging Diamond Interchange (DDI) is the preferred concept for a new interchange at this time. WSDOT believes it can optimize traffic flow and manage congestion better for travelers through the interchange. More than 80 DDIs have been built around the nation. WSDOT will build its first DDI in Lacey at I-5 and SR 510. You can see how a diverging diamond interchange works by viewing this DDI video on WSDOT's YouTube channel.