Hold short runway **
Stop, contact the tower to ask permission to cross the runway
Even emergency vehicles must contact the control tower.
At an airport with a control tower already have taxi clearance to cross all runways or get clearance from ATC to cross the runway. :)
Tower! Maintenance One, at Taxiway Alpha, request permission to cross runway 12
Depending on the airport and the regulations in place, any vehicle can cross the runway provided it is in radio communication with the tower and has had clearance to cross. The would also need to advise the tower when they had cleared or "vacated" the runway. In an emergency, the main vehicles given permission to cross or even enter the runway would be the "crash" trucks and the ATC supervisor. They would still need permission to enter the runway.
Stop at the runway hold line, contact control tower via 2 way radio to ask for permission to enter/cross
Tower! Maintenance One, at Taxiway Alpha, request permission to cross runway 12
Tower! Maintenance One, at Taxiway Alpha, request permission to cross runway 12
none of the above
Emergency vehicles, such as fire trucks and ambulances, may be authorized to cross a runway without contacting the control tower in case of an emergency. These vehicles are trained to respond quickly to urgent situations and may have direct access to the runway to provide immediate assistance.
Stop, contact the control tower for permission to cross.
Roger Tower. Once you've cleared the runway you tell tower" Vehicle one cleared runway two five on taxiway hotel."