The Scottish climate means that for much of the year our driveways are subjected to constant freeze-thaw cycles which can result in small cracks. These can be fixed by patching the affected areas. We would only recommend doing this if the cracks are very small and can be filled using a liquid filler.
However, if the crack is larger, we would advise replacing the driveway. Patching larger cracks will only provide a temporary solution and you will have to continually patch cracks that appear, making it uneconomical in the long run.