On the Fourth of July a couple of centuries back, the United States was founded on compromise, taking the good with the not so good.

It’s appropriate that today on the Vineyard, the fireworks, parades, flags and cookouts are served up along with traffic, crowds and chance of rain.

And for those involved with safety, service or transportation, it’s a day of continuous motion.

By 3 p.m., the entire Edgartown police force will be on duty, from the traffic directors to the police chief. More than 50 safety personnel will be patrolling the streets on bikes and all-terrain vehicles, walking around in plainclothes, or surveying the crowd from the cameras atop the force’s mobile command unit.

They don’t foresee any trouble, just a lot of people.

“It’s the only show on the Island tomorrow so, yeah, we’re expecting a big turnout,” Lieut. Tony Bettencourt said Thursday morning.

The Edgartown parade will start at 5 p.m. at the Edgartown School.

“It’s generally a family atmosphere downtown, up until the fireworks,” said chief Paul Condlin, explaining that after the display, many people head to the bars. “That can be a challenge. Up until then they’re a relaxed crowd, except when they find out their car’s been towed.”

Lieutenant Bettencourt said police have been preparing for days to make sure that doesn’t happen, issuing warnings in the parking areas that there will be no parking downtown today.

The police will start shutting off roads at 4 p.m. At 4:30 p.m., there will be no cars in the downtown area. The Chappaquidick ferry stops taking vehicles from 4:30 to 6:30 p.m.

Lieutenant Bettencourt’s advice: get downtown early. If you’re in the parade, get to the Edgartown School before 3 p.m. If you have a car, use the Park and Ride lot on Upper Main street. Ride in on your bicycle.

Streets will begin to open again around 6:30 p.m.

The parade will weave through the downtown streets, from Pease’s Point Way down Main street to North Water street and then will loop back to its starting point.

People line the streets every year searching for their favorite float. For many, that means keeping an eye out for Camp Jabberwocky, which has become a staple of the parade.

“It’s because of the fun that the campers and the counselors have fun when we do it,” said camp director Johanna Romero de Slavy. “It’s what we love to do and it gives people a taste of Camp Jabberwocky.”

This year, the camp will celebrate its 55th anniversary with the theme “Camp Jabberwocky throughout the ages.” They’ll have elements from various eras, such as disco balls and a yellow submarine, to show the life of the camp from the 1950s to 2008.

Because of its location along the parade route, and with a view of the fireworks, the porch of the Harbor View Hotel will most likely be overflowing today, as it has in years past.

“You stand there and you wave to everybody,” Patricia Wheeler, the hotel’s director of concierge services, said Wednesday. “It’s about the community. You don’t get a parade off-Island with the intensity that you get here.”

A couple approached her and asked where they should go on the Island for the holiday.

“Stay right here,” she replied. “You have a front-row seat.”

The hotel is completely booked and its restaurant is fully reserved. All staff are on duty and the hotel has increased security.

Things have also been busy at the Island’s entrances.

Bob Davis, treasurer of the Steamship Authority, said the ferries have been fully booked for vehicles for the past three days. Departures on Sunday for those with vehicles are also fully booked.

“We’re expecting a busy weekend,” he said.

The Martha’s Vineyard Airport has its full staff working.

Manager Sean Flynn said the airport will be busy stretching from Thursday to Monday morning.

But so much of the weekend depends on the weather, which is looking rather unpatriotic.

According to the Weather Channel, it will be mostly cloudy tonight with a 20 per cent chance of rain. There will be a light rain throughout Saturday and a 30 per cent chance of rain on Sunday.

The fireworks will begin at 9 tonight in the Edgartown harbor. Visitors and Islanders alike will be hoping for clear skies.