Oxfordshire County Council aims to repair dangerous potholes within two hours of being alerted, data obtained by the RAC Foundation shows.
That's the most common response time, with the slowest councils in the UK taking up to five days.
Hitting a pothole, or even swerving to avoid one, can ruin a car's suspension, steering or tyres, according to the AA.
In extreme cases they can cause serious accidents.
In 2018, the AA estimated potholes cost drivers and insurance companies an eye-watering £12 million.
It said: "The pothole epidemic has become nothing short of a national disgrace."
A Freedom of Information request by the RAC found that Oxfordshire County Council uses a "risk-based" approach to fixing potholes.
Not only will a pothole's size be considered, but also the potential impact on road users and volume of traffic.
That means deeper potholes on quiet lanes will be less of a priority than minor defects on a major route.
The local authority will only investigate potholes that are at least 4cm deep and 15cm wide.
That applies regardless of whether the pothole is on a quiet lane or a major route.
RAC Foundation director Steve Gooding said: “The total number of potholes being filled in might still be limited by a shortage of funding, but this approach at least means those that are most dangerous are fixed first.
“Those particularly vulnerable to potholes – cyclists and motorcyclists – might ask whether the speed of pothole investigation should be based solely on the risk to users.”
For less dangerous potholes that are earmarked for specific repairs in Oxfordshire, patching up could take up to a month.
And the least troublesome defects may not be repaired at all - but the council will monitor the pothole and consider including repairs in future roadworks.
The Local Government Association called for more funding for council-controlled local roads.
Transport spokesman Councillor Martin Tett said: “Keeping roads safe for all users is one of the most important jobs councils do.
“That’s reflected in the fact that local authorities are fixing a pothole every 21 seconds."
He added that councils need "consistent and fairer government investment in local road maintenance".