Can ‘detour’ mean ‘bypass’ in the sense of ‘to go around’?
In short, yes it can. Just.
Eg: "There's a traffic bottleneck in the next town, so let's bypass it/detour by taking the next left and using the lanes".
Note that you must bypass something, you can't just bypass. (Like 'enjoy' - you can't just enjoy, no matter how many restaurant staff tell you to!)
'Detour' does not only have this meaning of bypassing: on your journey, you can detour to visit another place before continuing to your original destination. However, in England we would probably favour the expression 'make a detour'.