Not all that successful at saving the likes of Hamburg and Berlin from being reduced to rubble by allied bombers.

Yes, I'd considered that truth, but they were only a part of what was a hopelessly doomed general defence effort. As far as their part in this defence was concerned, well they were often the only thing left standing after the raids, with their inhabitants mostly saved (their main function being as air-raid shelters) so in that respect I still believe they can be deemed successful.

The autobahn was not designed as a military project so it really can not be counted as one. In fact construction on the autobahn was halted during WWII. Furthermore in Germany the primary logistics mover was the railroad system. Completed sections of the autobahn did prove useful to allied forces and did inspire the Interstate Highway System in the US.

But truth be told the Germans did a very good job on what they have. Twice the roadbed depth, excellent drainage, aerodynamic curves It'd be nice if we could have built our interstates like that, especially the thicker roadbed, but with over 42 thousand miles in the system (vs Germany's 8 thousand) the cost is just too prohibitive.

:hmm2:
the effect of flak towers was easily and mightily eclipsed by
US 5" and 3" AAA using radar guidance, proximity shells and mobility for
protection in the same years as the few towers that were completed.
[edit] also there were a lot more than a just a few US AAA guns.
towers didnt catch on proximity triggers and radar guidance did.

The tank