Beginning June 30, 2010, controllers began issuing explicit instructions to cross or hold short of each runway that intersects a taxi route. More recently, FAA Regulation 91.129(i) has been changed to reflect the new procedures. The new regulation reads:
91.129 Operations in Class D airspace.
(i) Takeoff, landing, taxi clearance. No person may, at any airport with an operating control tower, operate an aircraft on a runway or taxiway, or take off or land an aircraft, unless an appropriate clearance is received from ATC. As a result, "Taxi to" is no longer used when issuing taxi instructions to an assigned take-off runway.
Instructions to cross a runway are now issued one at a time. Instructions to cross multiple runways are not issued. An aircraft or vehicle must have crossed the previous runway before another runway crossing instruction is issued.
This applies to any runway including inactive or closed runways.
Never cross a hold line without explicit ATC instructions. If in doubt ASK!
Reminder: You may not enter a runway unless you have been: instructed to cross that specific runway; cleared to take off from that runway; or instructed to line up and wait on that specific runway.