According to the AAA, which always seems to know these things in advance, 34.4 million Americans will be on the roads this holiday weekend. That's a 3.3 percent increase over last year's estimate from the auto club, in spite of the highest July 4 gasoline prices in our nation's history.

Apparently, there isn't a gasoline price high enough to keep us Americans out of our dearly beloved automobiles. So if we want to cut costs and conserve fuel, we'll simply have to bite the steering wheel and adjust our driving habits.

Oh, you've heard all that before?

You already know that you'll use less gas if you don't drive so fast on the interstates. You're fully aware that it's wasteful to take off at jet speed from stoplights just so you can beat the other guy to the next stoplight. And you're undoubtedly giving serious consideration to swapping your SUV for a Prius. (Yeah, right.)

In short, you've successfully ignored all the well-known conservation methods. But don't get complacent. The time may yet come, my friends, when you'll regret your failure to pay attention to the little things. Because as circus boss John Ringling North once said about the tower of midget acrobats, they do add up.

So in the spirit of Independence Day, as a patriotic American interested in freedom and less dependency on rich Saudis, let me offer some scientifically sound but previously untested suggestions that might not have occurred to you:

1. Lighten your car. It's a known fact that the more a vehicle weighs, the more fuel it burns. Here's the solution: Fill your trunk with helium balloons and inflate your tires with the same lighter-than-air gas.

Also, keep in mind that you are a major part of your car's weight. If you have struggled in vain with Atkins and South Beach, remember that every little bit helps. Get a haircut. If you're not already in the habit of doing so while traveling on business, leave your wedding ring at home. And do you really need both those contact lenses?

2. Avoid hills. Not all hills, of course; just the up sides. If your driveway slopes upward toward your house, have it excavated down to street grade. Climbing your driveway every day is a senseless waste of gasoline. After all, when you're home, you're home.

If all else fails, ask your employer for a transfer -- to the Kansas office.

3. Cut corners. Did you know that by careful maneuvering you can decrease the total number of miles driven between points A and B? Let's say you're in the right-hand lane of a four-lane highway. Whenever the road curves to the left, don't stay in the right, or outside, lane; it's the longer way around. Swerve quickly into the left, or inside, lane. And don't let any other cars or trucks bully you into switching back until the road curves to the right.

4. Minimize aerodynamic drag. Wind resistance is one of the biggest causes of low gas mileage, especially at high speeds. With today's sleek auto styling, there are only two protuberances sticking out into the wind stream and causing drag. So, you're just going to have to remove both side-view mirrors. Congratulations if you've already done so while backing out of your garage.

Also, it helps if you drive only in bad weather. The atmospheric pressure is lower and there will be less air resistance.

5. Steer into bumps. It's a fact of physics that when you hit a bump in the road, your tires bounce upward, momentarily losing contact with the road surface and eliminating friction. Less friction, of course, means more miles per gallon of gasoline. So study the road ahead carefully as you drive, and steer into as many bumps as you can.

But watch out for potholes; they have exactly the opposite effect. Fortunately, inept street crews are out there all the time over-filling potholes and converting them into bumps.

6. Maintain a constant speed. Acceleration wastes fuel, while maintaining a constant speed conserves it. And braking just throws away the energy you've built up while accelerating. So set your cruise control for 25 mph, keep it there all day, and brake only when confronted with something you can't drive over. Don't be intimidated by the drivers behind you. Ear plugs will block out their horns.

If we all cooperate in implementing these small measures, I guarantee that the price of gasoline will no longer be a concern. The roads and highways will be so clogged that no one will be able to drive anywhere.

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Robert L. Wolke is professor emeritus of chemistry at the University of Pittsburgh and the "Food 101" columnist for The Post. His latest book is "What Einstein Told His Cook: Kitchen Science Explained" (W. W. Norton).