In case there is an operational justification to fly other than direct routes below a certain altitude, e.g. when a military area is in the way, there is a good reason to create an alternative route to circumnavigate the area below that altitude. Yet, this is always a local affair, never involving a whole FIR. Another operational reason may be the separation between different flows of traffic, e.g. to separate strategically an inbound stream from the overflyers.
However, a division between upper and lower airspace as depicted on aviation maps is made for the entire FIR. I maintain that I see no operational reason whatsoever to continue with this relic from the past. It has to be regretted that the Euopean Union with its initiative to improve ATM has made a uniform upper/lower division level as one of its action items, which has been uncritically accepted by too many ATC people who should know better. In this way the European Union initiative will be much of a hot air movement. No operational impact but lots of administrative work. Jobs for the boys.
055166k: I understand there is a difference between route L9 with the beacon hops and the direct UL9, which has to be reflected on the charts. I don't know the local circumstances up there, but would you happen to know WHY the lower routes are different from the upper? Is it to circumnavigate a military area, or is it the lack of range of the VORs below a certain flight level (and if so, does that range coincide with the division level between upper and lower - which would be very fortuitous wouldn't it). Or is it true what I am thinking in my most suspicious moments that the authorities have been so little inventive or lazy that they never have adapted the beacon hopping route to new operational or technical advancements?