Tips for travelling Italy's autostradas: thank god for Autogrill

We recently finished a four-week research trip driving through Northern Italy. As we've spent a lot of time on Italy's autostradas (motorways, freeways), here are some tips to travelling the autostrada:
WHO: Every man and his dog drives the autostrada, from Italians doing the daily commute to work to truckies doing long-haul trips between countries. During holidays you'll be joined by campervanners and caravanners, who can be the most bothersome, generally driving well below the limit and slowing everyone down. Followed by drivers on their cell phones of course!
WHAT: Italy's autostradas are mostly dual carriageways and offer few places to exit, turn around, stop, rest, and refuel than freeways in many countries we've driven in, so always know where you're going, stay focused, fill up, and plan ahead. Or hope you see an Autogrill. Attached to fuel stations, these excellent one-stop-shops are a stand-up cafe, panini stop, book and music shop, delicatessen, and gadget heaven in one. You'll find anything here from a beach towel to a phone recharger.
WHERE: Autostradas criss-cross the country, connecting all major cities (see this list), the handiest being the A1 taking from Milan to Rome and on to Naples, the A4 from Milan via Venice to Trieste (although the area around Venice is almost always clogged), and the A14 running along the east coast from Bologna to Bari, which is picturesque.
WHY: The autostradas are fantastic for zipping between cities. Sit on 130 kph (the legal limit, although most Italians do 160 kph) and no sooner have you left one city that you realize you're already approaching another. Don't dare blink or you may miss a hilltop town or castle worth a detour. For cash-rich time-poor travellers the convenience and (mostly) smooth ride makes taking the autostrada worthwhile, however, budget travellers should be aware tolls are expensive and can add up. But these days, with the high cost of fuel, buses aren't cheap either, trains never were, and no other form of transport gives you the flexibility a car does.
WHEN: During some periods motorways can get just as clogged as the highways, so there are times to ditch the autostrada in favour of quieter country roads or simply staying put: on Friday afternoons in the warmer months avoid driving in the direction of beaches and lakes when Italians go away for the weekend; avoid travelling anywhere on a Sunday afternoon when everyone is returning home; and avoid any road during Italy's August vacation month, when everyone in the country is going anywhere they can as long as it's away from home and in the sun.
HOW: Make sure you're prepared:
1) carry lots of notes and coins: tolls are expensive, costing us anything from €1.60 to up to €14 for our most expensive trip
2) use the best quality maps you can find; the Italian Touring Club maps are excellent
3) know the route numbers you need, destinations along the way, and the city at the end of the line because Italy's road signage is terrible and the only constant is their lack of consistency: one destination may appear on one sign, but you may not see it again until it's time to get off and then it may be too late
4) know which exit to take to get to the part of the city you need (check with your hotel); some cities have two or three exits, generally a 'centro' (centre), sud (south), nord (north), oeste (east) or ovest (west)
5) stay alert - the autostrada exit and entry roads can be a nightmare, twisting and turning around, up and over each other like a tangled spiral (this is where you'll find bottlenecks, especially if it's anywhere near a port or industrial area); one wrong turn and you can waste an hour or more
Have I put you off? If you think the highways and back roads are better... well, that's another post!