Freiburg to Frankfurt- Suggestions?

Driving from Freiburg to Frankfurt in mid-July. Does anyone have suggestions for a scenic route to take? Lonely Planet suggests the B500 road... Has anyone driven this before? We would like to keep the driving time to around 4hrs and would just like to enjoy some nice scenery on the way. Thanks in advance for any tips!

Have a look in http://www.viamichelin.com and compose your own route. The direct route, via the motorway, should take about 2 hours and 45 minutes. Just add scenic routes to it and see what you come up with. Freiburg is so close to France that you could even take a route through the Elzas. On the map the B500 seems to have quite a lot of curves and I wouldn't be surprised if it would take you much longer than the 4 hours you specified.

If you have only 4 hrs, you cannot make big detours. You may nevertheless check Freiburg - Colmar/Ribeauville and either the road through the vineyards or the Route des Crêtes. For city breaks, check Colmar, Strasbourg, Heidelberg, Speyer.

As far as I know there will be big construction on the A5 in July around Karlsruhe so better avoid that part.

Agree with #2 about your timeframe. Just spend a part of your trip off the Autobahn. I recommend the strip Bruchsal - Heidelberg, both relatively small, nice alternative route and both towns some nice venues to visit if time is allowing. Adding the small but picture postcard-ish Ladenburg if - there again the worst trip-enemy - time allows.

Road constructions as #3 is indicating: yes. It's only a 15 minutes extra travel time in 'normal' circumstances'.

When are circumstances normal at that stretch? Even without construction I spend numeros hours in traffic jams around Kronau, best thing to do is get off at Bruchsal and take the B 35/36 to Hockenheim or the B 3 to Heidelberg.