I am find it highly unlikely that a commercial organization like BT would be allowed to run speedtest servers on the UK's academic network. I don't see how BT would even eligible for connection under the Eligibility Policy, let alone a speedtest server being allowed under the Acceptable Use Policy.
I did seem odd, but...
Go to:
https://www.speedtest.net/
Change server and search for "BT Lancashire Services", that gives you a Speedtest server hosted by
https://www.btlancashire.co.uk/, seemingly on Lancaster Council's Janet connected network ?
traceroute to
www.btlancashire.co.uk (194.150.176.82), 64 hops max, 52 byte packets
1 192.168.7.2 (192.168.7.2) 3.629 ms 9.904 ms 12.413 ms
2 * * *
3 172.23.64.141 (172.23.64.141) 39.100 ms 45.861 ms 36.487 ms
4 172.31.139.187 (172.31.139.187) 43.047 ms 37.575 ms 28.691 ms
5 188.31.255.54.threembb.co.uk (188.31.255.54) 31.918 ms 52.063 ms 45.317 ms
6 188.31.255.101.threembb.co.uk (188.31.255.101) 81.239 ms 55.091 ms 46.786 ms
7 188.31.255.189.threembb.co.uk (188.31.255.189) 62.809 ms 60.300 ms 48.285 ms
8 ae2.cr0-lon9.ip4.gtt.net (141.136.102.65) 31.282 ms 44.110 ms 59.335 ms
9 et-0-0-47.cr10-lon1.ip4.gtt.net (89.149.139.5) 47.366 ms 43.407 ms 59.258 ms
10 ip4.gtt.net (46.33.78.78) 53.256 ms 59.783 ms 50.092 ms
11 ae24.londtt-sbr1.ja.net (146.97.35.193) 40.476 ms 37.074 ms 34.435 ms
12 ae27.erdiss-sbr2.ja.net (146.97.33.14) 50.925 ms 46.263 ms 54.971 ms
13 ae29.manckh-sbr2.ja.net (146.97.33.42) 55.510 ms 45.600 ms 71.500 ms
14 ae25.manckh-ban1.ja.net (146.97.35.50) 60.638 ms 94.271 ms 40.391 ms
15 lancs-council.manckh-ban1.ja.net (146.97.40.50) 49.523 ms 56.419 ms 48.756 ms