while that can be done ( at least i believe ) without an update... it is a delicate issue - cause raising the prices too much can result in a countereffect ( blockade causing a huge increase of trade ) - or when its too little ... it has no effect.
it also involves that the admins ( or rather that cannon, cause i m not sure other admins are able to do it ) is informed about EVERY blockade - and not just the start of a blockade - but also the official END of it ( players tend to start things... but leave them run their cause without notice [ see bounties, which are rarely "resolved" but usually just forgotten ] )