Sorry, I didn't want to hijack the others here and my question is different. Unlike the other thread where there was a concern of driving on the autobahn, I plan to stay off the autobahn as much as possible as my goal isn't to get from point A to B as quickly as possible but to see as much as I can between point A and B. Examples include driving up the Rhine on B9 and along the Mosel on B53. I really don't want to be in a hurry so I can view what is around me as I drive and will want the opportunity to pull over as photo ops present themselves. How busy are these roads? Are there fairly frequent places to pull over? Is this type of plan possible?

Thanks.

>fairly frequent places to pull over?
Yes, perfect infrastructure. "Official" parking spots well marked every few kms. Probably unlike anywhere else in Europe. Many of those spots are full with trucks at night, but during daytime there's no problem. Traffic depends, but fairly havy everywhere. Main problem are trucks that use the federal highways because of the road toll on the Autobahn.

To make sure there is no confusion: The road toll on the German autobahn is for trucks only, not passenger cars. Austria is a different story.

Depends.
B9 between Bonn and Koblenz is a 4-lane freeway for most of the latter part. B42 on the other side of the Rhine is less busy, and a regular 2-lane highway.
When you check your routes on Google maps you see the freeway section in dark yellow/orange while the regular 2-lane highways are yellow.
B53 does not follow all the Mosel but only the upper section. The lower Mosel valley got the B49 or B416. All three are fine for your purposes.

Sometimes you will come across amazing scenery and will be looking for a place to pull over and not find anything until you get to a pull out with a totally obstructed view or no view at all! My husband is a photographer and he has been frustrated many times on our trips. But it's not just Germany. We've found this to be true everywhere!

Have driven all thru Europe......Germany to me is the most driver-friendly, great signs, autobahn a breeze, my only complaint would be that there seems to be major construction everywhere...the side roads are great especially those marked for tourism (romantic road/wine roads)....mk

I concur with Betty - I have driven the Mosel and Rhine and remember often having a hard time finding a pull-out when I needed it for a photo op. But that's no different from many other places in the world. Since I had a co-driver I sometimes shot photos out the window as we slowed down...which doesn't get you the best shots in the world, but it's better than nothing. If you are driving solo it becomes more difficult because it is hard to watch the scenery, the road, and look for a pull-off at the same time. If you are not in a rush then you should be willing to turn around and go back to find the right spot...and not hurrying is of course the best way to travel. The other option is to park where it is safe and legal and walk along the road (there are many walking/biking paths along the rivers) to get your shot.

If I had lots of time, I would probably do a river cruise on either of the rivers for the best unobstructed views of the castles and vineyards.

Be sure and pass by the Lorelei. It is a beautiful view of the Rhine

Thanks for the info everyone!

Pack a picnic lunch. Pull over and spend some time.