Was returning home from work and passing a radio station and tower on the east edge of town. was going over a bridge over the rail road tracks and sighted a single light a few hundred feet above my car. first i thought it was beacon light on transmitter tower and realized it was solid orange and not the tower light. as i got to the top of the bridge i looked back forward and saw 3 more. orange brightly glowing spheres. weather was extremely foggy and could only see a few hundred feet in any direction. this is a 2 lane road i was on and couldn't just stop. i slowed to about 15 miles and hour and was leaning forward to look up at them thru the windshield. i had already past the first. the other 3 were in view. lasted 20 seconds at most. but they were 2-3 ft round spheres glowing a bright but defined and non-flickering orange light. at first i wanted to believe they were chinese lanterns. but they were smooth round, and orange no flickering. they were moving east-south east fairly slowly. it was a calm foggy light. once i got home ,approx 2 minutes later, i decided to go look for them again. i drove around the area for 10-15 minutes stopping and looking all the way to the interstate and did not see them again.