A road crew supervisor

A road crew supervisor hired a nice-looking blonde woman to assist with painting the white line down the middle of the road.
He was skeptical about hiring her, but she appeared enthusiastic and told him that she really needed the job.
He explained to her that her work day would be to complete 2 miles of line on her road, and he set her up with her brushes and paint and got her started
After the first day, he was pleased to find that she did an excellent job and was able to paint 4 miles of road in her 8 hour shift.
He told her that she did an excellent job and how pleased he was with her progress.
On the second day, she completed painting 2 miles of road.
Her supervisor was surprised that on day one she had completed twice as much work, but did not say anything, as 2 miles of road was the amount that the job required anyway.
He decided to just accept it, and to look forward to the next day when he was sure she would pick up her speed again.
On day 3 he was shocked to learn that in her 8 hour shift, she only completed painting 1 mile of road.
He called her into his office and asked her what was the problem,
"On your first day, you completed 4 miles of road, on your second day, 2 miles of road, and now on day 3, you were only able to complete 1 mile of road.
Can I ask you, what is the problem?"
"Well,"
she replied,
"I keep getting farther and farther from the paint can."