The problem is likely that your ISP is routing some traffic via an overloaded peering point.

Running

traceroute -w 1 -q 5 -A <bwauth-IP> 1400

may provide more detail on this issue. The -A option causes 'traceroute' to show Autonomous System numbers with each route hop, where ASNs are Internet routing domains associated with different network providers. One can readily see where big increases in latency are occurring along the path and what peerings are associated with it. Note that some big increases are justified--such as with a hop over a transatlantic cable. Setting -q 5 (or bigger) causes traceroute to attempt each hop that many times. If you see asterisk characters, that's packet loss and may indicate congestion points.

Setting the packet size to 1400 will increase the probability that network congestion will impact the results.

Try pulling up

https: // torstatus dot blutmagie dot de

which shows IPs together with other relay attributes and experiment tracing to various major relays.