You are only legally allowed to pass a vehicle by going into the other lane of traffic under two conditions:
1) There is a dotted yellow line and there is no risk of causing an accident.
2) By doing so you are avoiding an accident.
It depends on the country you are in. Many countries drive on the left as a matter of course.
But in CAN and the US, you can drive in the left lane while passing another vehicle, legally.
(in the US) you may drive to the left side of the roadway (unless prohibited by signs) when operating on a one-way street or road - OR, at the direction of a police officer in an emergency situation.
Many countries, such as Britain, drive on the left side of the road, with the driver's seat on the right of the car. If you're in a right country, then don't drive on the left.
over the double yellow line
In practice, It is acceptable to increase the speed of your vehicle over the legal speed limit to pass or overtake another vehicle. Legally, it is not permitted. If the other vehicle is already at the speed limit, you should not be passing it. If it were a police car you were passing, at any speed above the speed limit, they could stop you.
never
For a country with right side traffic you should as a rule overtake a vehicle on its left side. But on a bicycle it's allowed to overtake on the right side as well.
Because - as you overtake the vehicle in front, high-beams will be reflected straight back at the driver - through their mirrors. Low beams are angled more towards the ground.
(in the US) On multi-lane roadways - The far right lane
So long as you are not speeding as you are passing yes. However if the vehicle you are passing is traveling at the speed limit the cop that books you will contend that you had no reason for passing.
In practice, It is acceptable to increase the speed of your vehicle over the legal speed limit to pass or overtake another vehicle. Legally, it is not permitted. If the other vehicle is already at the speed limit, you should not be passing it. If it were a police car you were passing, at any speed above the speed limit, they could stop you.
The speed limit is exactly that - the speed limit. While a reasonable excess of speed might be overlooked when overtaking another vehicle, there is no guarantee. You can be pulled over and cited for speeding, still.
You should only overtake if it is safe to do so.
No, they cannot. A continuous white line means that no vehicle should overtake another, especially when one is turning.
No. If the vehicle you are passing is going at the correct speed, why should you need to overtake. When overtaking a vehicle you should ensure there is enough clear road ahead of you to pass the vehicle without over speeding. If this is not the case you should not attempt an overtaking manoeuvre.
You should use your low beams to avoid blinding the driver ahead as you lights reflect in his mirrors.