Federal transportation officials are investigating a civil rights complaint filed over the $1.2-billion I-70 renovation and expansion in Denver. Self-described environmental law firm Earthjustice filed the complaint on behalf of opponents in two nearby, mostly minority communities that say the project will further harm neighborhoods divided by the highway. State transportation officials have been “extremely sensitive” to community and environmental issues during planning, says a spokeswoman. The project has been delayed by about six months for environmental review and selection of the public-private team that will finance and build it. Work should begin in 2018.