Police were called to the collision, involving a Mini Cooper and a Vespa Piaggio scooter, at 11.21pm on Tuesday 29 December.
The rider of the scooter, Benjamin Ringe, 30, of Copnor Road, Portsmouth, died from his injuries.
Paying tribute to him today, his family said: “Ben will be deeply missed and forever loved by all of his family, friends and all that have had the pleasure of knowing him.”
His twin brother added: “The best twin anyone could ever ask for. Love you always my brother.”
Ben’s partner said: “No words can describe how heartbroken we are to have to say goodbye to you. You are an amazing dad and a great step-dad. We love you so much and will miss you more than you will ever know. You will always be my best friend and my soulmate.”
Officers are continuing to investigate the exact circumstances of the collision.
Anyone with information should call 101, quoting 44200499342.