Driving circle friends: Is the whole journey from Edinburgh to Skye on the motorway ?

How do you want to go, to enjoy the scenery along the way, to stop, to eat and drink, or to go at top speed without stopping? The former is basically A82A87, with only a small section of highway, the rest of the road has very narrow lanes, but when cars pass each other, their speeds are basically both around 50 miles per hour. If you choose the latter, you can take M90A9 to Inverness directly, with a long section of highway that is very similar to the expressways in China, but there are basically no scenic spots except for grasslands, no villages to pass through, and no good places to stop and rest. If you don't stop at all on M90A9 from Edinburgh to Inverness, and maintain a speed of more than 60 miles per hour, it will take you only three and a half hours.