I don't think the problem is that of signage. The issue is zero-tolerance. It expands beyond simply parking. The lack of discretion that computerised solutions

I don't think the problem is that of signage. The issue is zero-tolerance. It expands beyond simply parking. The lack of discretion that computerised solutions seem to beget. The incentive structure that means parking wardens feel inclined to ticket for being 10cm over a bay.