Do police not understand that this sort of thing undermines respect for the law, and for themselves?

Kate Wilson, 29, said she was nursing a strained calf muscle and propped her right leg up on an empty seat while riding the D train in Borough Park about 1 a.m. Sunday.

The car was sprinkled with about five straphangers, she said, when three cops told her to step off the train at the 36th St. station, just one stop from her home.

“There were empty seats all around the whole car,” she said. “It was ridiculous. It wasn’t a conversation. I felt harassed.”

As one cop began to write her a summons for obstructing seating, Wilson tried to reason with the officers and told them she ran 4 miles through Prospect Park the day before.

“I told them that I had run a race and my leg had been injured,” she said. “But, no, they didn’t care.”

She continued to protest until the officers told her she should “be grateful” she wasn’t getting cuffed, she recalled.

“I asked them if they had bigger fish to fry,” she recalled. “The police officer said, ‘Yeah, but we’re frying this one now.’ ”

So she gets slapped with a $50 fine, misses the next train, and ends up walking home. And predictably, on the walk…

“I walked away with a $50 ticket and didn’t see a single cop along the streets to my home,” she said. “Three cops on the platform and no cops on the street.”

She’s just lucky she wasn’t running an illegal lemonade stand.