FAA defines it as "Any occurrence at an aerodrome involving the incorrect presence of an aircraft, vehicle or person on the protected area of a surface designated for the landing and take off of aircraft." [0]
Many runway incursions run no risk of any accident, but are still flagged as issues, investigated, and punished if appropriate.
[0] https://www.faa.gov/airports/runway_safety/resources/runway_...
And the cost of investigating 1,700 should be within the budget.
If 1,700 is a minuscule fraction of all runway uses (as it likely is) then investigating it should be a proportionally minuscule amount of the budget.
* https://en.wikipedia.org/wiki/Runway_incursion#Definition
* https://www.faa.gov/airports/runway_safety/resources/runway_...
All incursions (in the US) are tracked:
* https://www.faa.gov/airports/runway_safety/statistics
Given there are ~45,000 flights per days in the US (and so aircraft and vehicles would move hither and fro around an airport for each flight), 1700 feels like a small number.
Human can misspeak or mishear instructions, but if they were communicated and understood correctly (a read back was correct), but the pilot had a 'brain fart' and went forward instead of stopping, how do we eliminate brain farts?
See 5-2-5 for an example:
https://www.faa.gov/air_traffic/publications/atpubs/aim_html...
NOTE- Previous reviews of air traffic events, involving LUAW instructions, revealed that a significant number of pilots read back LUAW instructions correctly and departed without a takeoff clearance. LUAW instructions are not to be confused with a departure clearance; the outcome could be catastrophic, especially during intersecting runway operations.
The older term was "hold short runway X" and that was too close to "hold runway X" - the first meant do NOT enter the runway, the second meant enter and line up but do NOT takeoff.
We talk about Vision Zero for streets. Vision Zero is actually achievable in aviation.