Discription of Events: It was pouring down rain and I was at a stoplight. I let someone in the opposite lane who had their turn signal on go before me since I was at a stop light anyway. The driver behind me lost it and laid on his horn. He switched lanes, accelerating and almost hitting the person I was letting turn in. He then switched lanes recklessly, nearly swerving into other cars in the lanes. I laid on my horn as well because he was terrifying me. He tailgated overs and proceeded to honk at people he thought were going too slow on a 35 MPH road