The roads in Sheffield are in a terrible state of repair, and in places resemble the belgian pave used for accelerated ageing by motor vehicle manufacturers during testing. Typically 2,000 miles of belgian pave represents 50,000 miles of "normal" use.
I myself had to replace all the bushes, balljoints, springs, and dampers on my own (used but by no means broken when I moved here) MX5 within the 8,000 miles of living and commuting in Sheffield. My new motrorcycle bleow out the fork seals twice within 250 miles of city use, due to generally poor road surfaces rather than any large potholes. (since sold, and looking for an off-road bike) My housemate's brand new Suzuki Swift has been back to the dealer multiple times for wheelbearings and balljoints within the first 3yr/60,000 mile warranty period. My kidneys and my brain tell me that this is no co-incidence, but the City Council disagrees.
I hypothesise that looking at MOT failure data for Sheffield versus say York, or better yet the west wales or the west country (where I know the roads to be in an adequate state of repair) will show a statistically significant difference in the proportion of steering and suspension failures. (keep it to bushes, balljoints, dampers, springs and other components directly affected by potholes - not gaiters and suchlike)
I would be particluarly interested in the data for buses and taxicabs, as these spend most of their lives in the city. Vehicles would want to be grouped by age/brand/segment so as to compare like with like (eg - no comparing farmer's 20 year old cavaliers with stockbrokers 3 year old bentleys)
This data could be used to support or refute the claim that Sheffield City Council has been negligent in their maintenance of the highways, or that they have squandered the rate-payers taxes inappropriately. The aim would obviously be to get the roads repaired to a state where they are no longer dangerous in themselves and no longer cause vehicles to become dangerous through damage.