Law enforcement sources tell TMZ, Lindsay was pulling in to park her Porsche Cayenne near the Dream Hotel in downtown NYC when -- at a very low speed -- she allegedly hit the knee of a 30-something year old man.

We're told one of Lindsay's passengers in the SUV got out and checked the car for damage ... and then LiLo and co. went inside the hotel.

We're told someone called police while Lindsay was inside ... and when she walked out of the hotel -- around 2AM ET -- officers arrested her.

According to our sources ... Lindsay was booked for leaving the scene of an accident -- a misdemeanor -- and then released with a desk appearance ticket ... meaning she did not have to pay bail before release.

We're told alcohol was not involved.