Infrastructure quality in United Kingdom is rated to be at 4.16. It indicates a good quality - roads, railroad, ports and other facilities are adapted and regularly maintained to handle high levels of traffic at all times, as well as most probably there are special facilities for handling high intensity and/or special traffic or vehicles (e.g. motorways a.k.a. autobahns and deepwater ports). https://www.confiduss.com/en/jurisdictions/united-kingdom/infrastructure/