Highway Traffic Act 

Section 147:

(1) Any vehicle traveling upon a roadway at less than the normal speed of traffic that that time and place shall , where practicable, be driven in the right-hand lane then available for traffic or as close at practicable to the right hand curb or edge of the roadway 

(2) Exception - Subsection (1) does not apply to a driver of a ,

	(a) vehilce while overtaking and passing another vehicle 
	proceeding in the same direction
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Section 148 
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(5)Vehicles or equestrians overtaking others -
Every person in charge of a veichle or on horseback on a highway who is overtaking another vehicle or equestrian shall turn out to the left so far as may be necessary to avoid a colision with the vehicle or equestrian overtaken , and the person overtaken is not required to leave more than one-half of the roadway free