A request by RTD for an extended waiver to operate two rail lines has been approved by the Federal Railroad Administration.

The waiver, which covers a five-year period, is on the University of Colorado A-Line and the B-Line, according to an RTD news release.

The FRA’s railroad safety board “determined that, subject to certain conditions, granting further relief to RTD on the A- and B-Lines is in the public interest and consistent with railroad safety,” federal regulators said in a written response to RTD.

The waiver is prompted by RTD’s struggle to gain regulatory approval of automated crossing gates on the two lines.

On Wednesday, state regulators denied RTD’s request to change the timing of crossing gates on several of the metro area’s commuter rail lines. The Colorado Public Utilities Commission, in a unanimous decision, concluded that the district’s latest at-grade crossing plan did not enhance safety for those driving or biking over tracks.

The FRA waiver approval does not supersede the CPUC’s “regulatory authority concerning grade crossings,” the RTD news release said.

The waiver approval by the feds gives RTD more time to address the issue of dodgy crossing gates. Crossing guards will remain at gates on the lines until the FRA approves RTD plans to remove them.

The FRA has not yet responded to RTD’s separate request to resume full testing on its G-Line.