It's not easy to break bad driving habits, but if you don't, the money you lose on gas could wind up breaking your bank.

Here are six ways drivers typically waste gas every on every trip:

1. Racing away from green lights

When the light turns green, you don't have to take off as quickly as possible. That pedal under your right foot is called the "gas pedal" for a good reason. The more you press down on it, the more gas you're pumping into the engine.

2. Racing up to red lights

When you're driving down the street, and you see a light red light or stop sign up ahead, you should lay off the gas sooner rather than later.

3. Confusing the highway with a speedway

Even if it doesn't involve hard acceleration, speeding wastes gas. The faster you go, the more air your vehicle has to push out of the way. It's like moving your hand through water. The faster you try to move your hand, the harder the water pushes back.

4. Bumper-buzzing

Tailgating wastes gas. Every time the driver ahead taps his brakes, you have to slow down even more than he did. (That's because you can't react immediately so you have to slow even more because you're slowing down later.) Then you accelerate again to get back up to speed and resume your bumper-buzzing routine.

5. Driving standing still

You've probably heard that it takes more gas to restart a car than to let it run. Maybe that used to be true, but it isn't anymore. With modern fuel-injection engines, it takes very little extra gas to restart a car once it's warmed up.

Idling, meanwhile, burns about a half-mile worth of gas every minute, according to the US California Energy Commission. That's why hybrid cars shut down their gasoline engines whenever they stop, even for a moment.

Bonus tip: Don't idle your engine to let it warm up before driving. It does your engine no good and it wastes gas. Instead, start driving right away, but drive gently until the engine is warm.

6. Short hops

For really short trips, take advantage of the opportunity to get some exercise. Try walking to the store instead of driving. You can save gas and burn a few calories instead.