I agree that more gas stations would be helpful, but only if they design it so it doesn't lead to more traffic flow issues. If you remember when TruckersMP released the CD "highway" on April 1st, they redesigned the gas station near Calais and they added traffic lights, so people can "safely" enter and exit the gas station, which just decreases the traffic flow substantially.
My suggestion is to add a special roundabout, called the "Turbo Roundabout" (common in The Netherlands) at the entrance and exit of the gas stations:
Roundabouts, in my opinion, are 100% superior to intersections (especially with traffic lights). They are safe and very fast.