A local controller witnessed an unauthorized runway crossing. The reporter suggested the use of prec...

Narrative:

I was working local with a DH8 on approximately a 2.5 mile final cleared to land; when I noticed a vehicle; on ground control frequency; cross my active runway southbound on taxiway a without coordination. After telling ground the vehicle just crossed [the] runway; we started discussing what happened. I did not hear the transmissions leading up to the event; only saw the vehicle during my scan. To keep this from occurring again; don't use the phrase; 'proceed as requested.' instead state the exact taxiways and hold short or cross instructions even if they are the same as requested. Vehicles operating on the movement areas should be trained to never accept; 'proceed as requested;' as a runway crossing clearance. They should be trained to always hear the phrase; 'cross runway xx at Y;' or otherwise question ATC to ensure you are both on the same page. Vehicles that do not need to check taxiway conditions; lights; etc. Should try to use perimeter roads as much as practical; especially when a runway crossing is involved if taxiways are used. Ground/local must always make eye contact with the vehicle/aircraft or verbally confirm the position and request before issuing instructions.

Original NASA ASRS Text

Title: A Local Controller witnessed an unauthorized runway crossing. The reporter suggested the use of precise and direct phraseology for ground vehicles.

Narrative: I was working Local with a DH8 on approximately a 2.5 mile final cleared to land; when I noticed a vehicle; on Ground Control frequency; cross my active runway southbound on Taxiway A without coordination. After telling Ground the vehicle just crossed [the] runway; we started discussing what happened. I did not hear the transmissions leading up to the event; only saw the vehicle during my scan. To keep this from occurring again; don't use the phrase; 'proceed as requested.' Instead state the exact taxiways and hold short or cross instructions even if they are the same as requested. Vehicles operating on the movement areas should be trained to never accept; 'proceed as requested;' as a runway crossing clearance. They should be trained to always hear the phrase; 'cross Runway XX at Y;' or otherwise question ATC to ensure you are both on the same page. Vehicles that do not need to check taxiway conditions; lights; etc. should try to use perimeter roads as much as practical; especially when a runway crossing is involved if taxiways are used. Ground/Local must always make eye contact with the vehicle/aircraft or verbally confirm the position and request before issuing instructions.

Data retrieved from NASA's ASRS site as of April 2012 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.

Attributes
ACN	956703
Time
Date	201106
Local Time Of Day	1801-2400
Place
Locale Reference	ZZZ.Airport
State Reference	US
Environment
Light	Night
Aircraft 1
Make Model Name	Dash 8 Series Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	Final Approach
Flight Plan	IFR
Aircraft 2
Make Model Name	No Aircraft
Flight Phase	Taxi
Person 1
Function	Local
Qualification	Air Traffic Control Fully Certified
Events
Anomaly	ATC Issue All Types Deviation - Procedural Clearance Ground Incursion Runway

A local controller witnessed an unauthorized runway crossing. The reporter suggested the use of precise and direct phraseology for ground vehicles.