We're going to be driving in Tuscany and Umbria in late June, and it looks like we'll be driving from Terni to Lucca in one day. Any suggestions for routes, sights along the way, somewhere to stop for lunch? The SS1/E80 (via Aurelia?) looks interesting....
I'd say it depends on what other areas in Tuscany you'll be visiting during your trip. You have basically two choices:
either take the A1 that passes through Florence which takes a little more than 3 hours OR follow the E80/Via Aurelia that goes through Grosseto up along the coast. This one adds about an hour to the drive... smaller roads not just a more round-about way to get to Lucca.
Both pass through beautiful areas that merit seeing - the A1 passes near Montepulciano and Arezzo. It passes through Florence. Will you be heading back through here later on? There are many villages near the road but you have to know the exits - you'll have to get off and drive a little in either direction to get to interesting spots, especially for lunch. The only choice on the road itself are the pit stops for gas and food called "autogrill" and they are not known for their culinary offerings.
If you are not coming back to the area to the south of Siena on your vacation, I'd definitely get off and go through Montepulciano and from there head to Montalcino for lunch. From there you can then head up towards Siena (a brief visit to the center for sure!) and then pass Florence on your way to Lucca instead of heading back to the A1. Assuming you'll be heading to Florence on another day, right?
The other road offers a chance to see the Tuscan coast. If you will be inland for the rest of your vacation, then I'd recommend taking this road to see this side of Tuscany on your trip up to Lucca.
I'd probably skip Grosseto (it is nice but overall pretty small) and stop in the area around Castagneto Carducci, another wine growing region in Tuscany. You'll pass lots of villages so stop for lunch wherever something inspires you. You'll find a lot of local trattoria where it is hard to eat badly.
If you want to stop for lunch right along the coast, then I'd stop before. When you are in Grosseto, leave the A1 and head towards Castiglione della Pescaia or Marina di Grosseto. At the end of June, you'll have lots of locals around. Another option is Livorno. Do you like seafood? Livorno is well-known for their Cacciucco alla livornese, a seafood soup with tomato and wine served with bread.
We took the E45 from San Gemini (leaving at about 10:00am), turned west at Perugia, past Lago Trasimeno, then went up to Cortona (yes - because of the book/movie..). It was very busy, but we had a nice lunch in the square, and shopped at the market. After lunch we zipped past Siena (which we had been through on our way down), on our way to San Gimignano. We had hoped to spend more time there, but it was even more busy than Cortona (this was a Saturday), so we weren't able to stop. We then took the SR429 - which was a smaller road than I'd expected, but was an enjoyable drive - up to the Fi-Pi-Li to Pisa. We then took the SS12 to Lucca. This was another quiet road that was quite beautiful to drive. Aftre a few wrong turns we found our B&B just outside the walls and spent two nights in Lucca.
We then returned to Florence for our last night in Italy (we had spent three nights there two weeks earlier to begin our trip). The only driving miscue happened when we were returning the rental car in central Florence. I missed the turn I was supposed to take, and took the next left instead, passing a sign with the letters "ZTL" on it. I thought "uh-oh - I wonder if that's the congestion charging zone?", but it was literally about 30 seconds before I returned the car (I was in the ZTL for about 10 seconds). About two months later I noticed a 50 euro charge from the rental agency on my credit card statement. About another month later, I got a letter from "European Municipal Outsourcing" detailing my transgression and offering me a chance to pay the 90 euro fine before receiving the official notice. I didn't pay, and haven't yet received the official notice, though as I understand it I won't be in the clear for another six months or so.
Overall, I wish we could have taken about 3 days to do the drive. There was a lot we missed, but it gives us a reason to go back!