<VV> US Roads, Signage, European Roads

[hallgrenn at aol.com]

Just my $.02 worth:
In my career I have worked with local road engineers in Maryland, Virginia and the District of Columbia. I agree with the increasing use of roundabouts, and in congested areas, jug handles.  They do reduce collisions and speed traffic through an intersection.  They are relatively unfamiliar to a lot of Americans so when encountered we tend to be a bit more alert.  
Hugo, the white stripes across the road are most likely there to help police aircraft enforce speed limits.  There will be at least two a tenth or a quarter mile apart so your time over distance can be used to clock your speed.  Most states will have a periodic warning sign alerting you to aircraft being used to patrol the area for speeders.  Road signs that denote directions that seems to be in conflict with a route's odd (north/south) or even (east/west} numbering let you know the local direction the road is taking.  Quite helpful in more densely built-up areas.  As you noted the odd of even route number only refers to the starting and ending points of the road.
In reference to European road signs I only have experience with central and northern Europe and the UK.  I've found the signage to be well maintained and informative (Americans who plan to drive there really should take an hour or two before arriving to learn what the various road signs mean--for their safety and the safety of others on the road with them).  German roads carry a very heavy burden from their use by other countries trying to get from the north to the south or vice versa. One learns to be more alert to drivers with non German license plate when driving on the Autobahn.  And no, the Autobahns do not have unlimited speed limits except in open country away from cities.  If you are in an unlimited speed limit area then you really have to look out for the drivers from other countries.
Finally, in my experience, the first budget item to be reduced in any highway budget (or any government) budget is signage.  The richer the state or country the more likely the signage with be thorough and well maintained. 
Bob Hall