Imagine your computor workstation is in the middle of the road. You are allowed to have a metre of space between you and the traffic, which you can mark with cones. You would feel pretty bloody vulnerable. If you are sitting in one place you are probably pretty safe.
How about cleaning the car? Dont step back to admire your handiwork, Don't chase the polishing cloth if the wind gets it. There are generators and maybe a compressor roaring away, you can't rely on hearing traffic passing. The trucks aren't so bad, the drivers are professionals. It's you we worry about......
Rest Area 300m