Tyre damage can usually be traced to a particular problem based on how the tyre has worn or failed, and cuts to tyres would generally be caused by the impact of a object on the road or by very poor road conditions such as potholes, although it is unusual that you have experienced this on three tyres.

However, 20,000 miles is a good distance to get from a tyre, so it may be that they were worn to the point where they became more susceptible to damage. Although the legal limit for tread depth is 1.6mm, tyre manufacturers recommend replacement at 3mm to avoid a loss of performance. When replacing tyres we would also suggest four-wheel alignment to ensure your vehicle is within factory tolerances.