road conditions - Excellent Road Conditions except few Dangerous Turns (Hairpins) BE VERY CAREFUL in DRIVING THIS AREAS.

accommodation along the way - Salalah to Muscat can be completed in 10 Hours. No need for any accomodation. On extreme cases you can take a break on the road itself.

is it possible to do this trip comfortably in 4 days - Salalah to Muscat and back to salalah can be done easily in 4 days.

any special issues or problems - No special issues or problems as of I know.

highlights along the way from Salalah to Al Ashkarah - NO IDEA :).

Have a nice and pleasant trip