Two new light-rail lines in Aurora and Arvada will open later than expected.

RTD had long planned to have the new R and G lines in service before the end of 2016. But the Denver Business Journal reports it’s going to miss that deadline.

The federal government says RTD can’t start operating the G line through Arvada until it fixes problems with street crossings on the A line to the airport and the B line to Westminster.

Other technical problems will delay the opening of the R line along I-225 in Aurora until after the start of the new year.