Martha's Vineyard for July 4th?

Travel Info
I am planning a trip to Martha's Vineyard (in MA) for July 4th, but have never been there before. I am unsure whether I should drive out to get the ferry Tuesday evening (July 3rd) around 6 pm or Wednesday morning (July 4th) around 7 am. I live in MA, so I would be driving down 495 to the Bourne Bridge. Will the traffic be heavier the night before or the morning of July 4th? If anyone has gone to the Vineyard for July 4th, I would appreciate some advice. Thank you, and I wish you all fun holidays as well!

Travel Tips

I would definitely go early in the AM. I've been there and dont it on July 3rd. The traffic was bad! It will take your hours. I bet the early AM will be a bit better. Leave the earliest you can! O yes and I am very jealous. : )
Others

Oh my god i LOVE marthas vineyard my family and I go every year. My family has a boat so we usually take our boat, but driving the day of the 4th will DEFINITLY be crowded. Are u planning on staying for a few days? or what? Because its pretty pricy to get a car on that ferry, which is the steamship authority. Go to that website and look at fares. steamshipauthority.com. But if u dont want to, walking around the vineyard is fine! You can take a bus ALL around for like 5 dollars. wicked cheap. the vineyard is beautiful. Oak Bluffs and Vineyard Haven i believe both have fire works. Make sure you go to Aquinnah, and the beach there its GORGEOUS. Also, South Beach is very nice near KATAMA. If u have any questions just email me! I love it there =)
Okay i hope you know that the car ferry has to be booked at least 6 months in advance. Im going in August and I had to book the ferry in Febuary and I couldnt get on until 8pm.
Plus, its a lot of money, you should just take the high speed and carry all your stuff.
Martha's Vineyard is amazing, I love it. Im sure you'll have a wonderful time.
The earlier the better. The earlier the better, I will repeat my self the earlier the better.

You will have lots of fun
I take it you're planning on leaving your car in the lot on the Cape and taking the ferry over. You will need to book a room now if youplan on staying over. And I would recommend going the night before. The lots will be packed on the 4th. Make your reservations now - both for the boat and for a hotel room. Good luck and have fun!