Arguments about whether a driver stayed within the track occupy a disproportionate share of race weekends. The problem is created by circuit design rather than by driving standards.
Run-off used to punish itself
On circuits bordered by grass or gravel, a driver who ran wide lost time immediately and risked ending his race.
No rule was needed, because the consequence was physical and instant. The limit enforced itself through lap time.
Paved run-off removed that. Asphalt beyond the white line is often as grippy as the circuit, so a wider line can be faster rather than slower.
Safety drove the change
Gravel traps decelerate a spinning car but can also launch or overturn one, and they leave a stranded car in a dangerous position.
Paved run-off allows a driver who loses control to slow under braking and rejoin, and it serves motorcycle racing far better at circuits shared between the two.
Given a choice between an enforcement problem and a safety problem, organisers chose the enforcement problem, which is the correct trade.
Detection is a large-scale technical task
Determining whether any part of a car remained within the line requires monitoring every car at every corner for the entire session.
Loops embedded in the surface and dedicated cameras now handle much of this automatically, flagging incidents for review rather than relying on observation.
Even then, judgement is required for cases involving a car forced wide by another, which no automated system resolves on its own.
Enforcement has to be consistent to be accepted
Drivers explore the limit continuously, so any corner where the rule is loosely applied will be exploited within a few laps.
Applying the rule at some corners and not others invites the argument that the boundary is arbitrary, which is why blanket application became standard despite producing large numbers of deleted laps.
Consistency across a season is harder still, since each circuit presents different corners where leaving the track actually pays.
Physical deterrents are returning
Gravel strips placed just beyond the line, raised kerbs and drainage channels restore a cost to running wide without removing the run-off behind them.
These solutions are circuit-specific and expensive, and they have to satisfy the requirements of every category that uses the venue.
The direction of travel is clear, though: making the limit self-enforcing again is more durable than adjudicating it thousands of times a weekend.