Passing on the Left
According to Tuning Up For Drivers on page 102, passing other vehicles is a manoeuvre that should be used sparingly. If you’re behind a vehicle that’s going well below the speed limit, you may want to pass. But if it’s not very far to where you plan to turn off, then passing may not be smart.
The First Question to ask Yourself
Do I really need to pass that vehicle ahead of me? It might be wiser to stay where you are until a better opportunity to pass presents itself.
It Must be Safe to Pass
A quick check of the Motor Vehicle Act finds section 159. It simply states that a driver of a vehicle must not drive to the left side of the roadway in overtaking and passing another vehicle unless the driver can do so in safety. Of course, this means everyone's safety, not just that of the driver doing the passing.
Having a Clear View
Section 160 requires that a driver of a vehicle must not drive to or on the left side of the roadway, other than on a one way highway, unless the driver has a clear view of the roadway for a safe distance, having regard for all the circumstances.
Do you consider anything other than whether the oncoming lane is empty or not? Intersections and driveways could be the source of trouble as the drivers turning right from them tend to look to their left for conflicting traffic.
The road ahead is straight, but it may not be flat. Vertical view obstructions, a dip in the road, can temporarilty hide and oncoming car completely.
Do the Lines Allow Passing?
Now we have to consider section 151 which tells us how to proceed depending on the lines painted on the road at the point where we wish to pass. Each solid or broken line, or combination of the two may permit or forbid passing on the left according to the type and color of the marking.
Once we have decided it is safe, we can see sufficiently far, and the lines permit the movement, section 158 now says that a driver must cause the vehicle to pass to the left of the other vehicle at a safe distance, and must not cause or permit the vehicle to return to the right side of the highway until safely clear of the overtaken vehicle.
Remember the Two Second Rule? Don't tailgate prior to passing and when you move back to the right, don't force the driver behind you into a tailgating situation.
Tell Everyone What You Intend to Do
Before we move to start or complete the pass, we must return to section 151 which requires us to make the appropriate signal when we move from one lane to another.
Speeding to Pass
Finally, section 146 prohibits us from exceeding the speed limit in order to pass. If you must speed in order to pass the vehicle in front of you it may be that you have chosen the wrong place to do it or that you don't need to pass at all.
The pedal of choice to react to an unexpected situation could be the brake, not the accelerator.