A driver in a line of traffic that is merging with one or more lines of traffic travelling in the same direction as the driver must give way to a vehicle in another line of traffic if any part of the vehicle is ahead of the drivers vehicle.
Note 1 : Drivers vehicle is defined in the dictionary.
Note 2 : For this rule, give way means the driver must slow down and, if necessary, stop to avoid a collision see the definition in the dictionary.
Example
Giving way when lines of traffic merge into a single line of traffic
Vehicle B must give way to vehicle A