West Chester Township Trustees were joined by Butler County Engineer Greg Wilkens Tuesday to mark the completion of the Diverging Diamond Interchange project at I-75 and Union Centre Boulevard. The DDI concept basically flips the traditional directions of traffic on the overpass. Wilkens says safety will increase and wait times will decrease at the interchange, where 50,000 cars drive through daily. There is still landscaping to complete over the coming weeks, but it won't effect motorists. The price tag for the project was nearly $20 million, paid for by Tax Increment Financing.